S1 Supporting Information

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Supporting Information Alkene Hydrosilylation Using Tertiary Silanes with α-Diimine Nickel Catalysts. Redox-Active Ligands Promote a Distinct Mechanistic Pathway from Platinum Catalysts. Iraklis Pappas, Sean Treacy, and Paul J. Chirik* Department of Chemistry, Frick Laboratory, Princeton University, Princeton, New Jersey, 08544, United States

[email protected]

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Table of Contents I. General Considerations

3

II. Full Ligand Screen for the Ni-Catalyzed Hydrosilylation of 1-octene.

5

III. Preparation of Nickel Complexes

7

IV. Nickel-Catalyzed Alkene Hydrosilylation Using Ni(2-EH)2

9

V. Deuterium Labeling Experiments

11

VI. Procedure for the Method of Continuous Variations

12

VII.Quantification of H2 Generation

14

VIII. Beer’s Law Plot Data

15

IX. Characterization of the Products of in situ Activation by HSi(OEt)3

16

X. 10-gram Scale Hydrosilylation

17

XI. Silicone Fluid Crosslinking

20

XII. Kinetics Experiments

21

XIII. DFT Calculations

24

XIII. References

33

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I. General Considerations. All air- and moisture-sensitive manipulations were carried out using standard high vacuum line, Schlenk or cannula techniques or in an M. Braun inert atmosphere drybox containing an atmosphere of purified nitrogen. The M. Braun drybox was equipped with a cold well designed for freezing samples in liquid nitrogen. Solvents for air- and moisture-sensitive manipulations were dried and deoxygenated using literature procedures.1 Deuterated solvents for NMR spectroscopy were distilled from sodium metal under an atmosphere of argon and stored over 4 Å molecular sieves. Nickel 2-ethylhexanoate (Ni(2-EH)2 / Ni(O2CC7H15)2) (% 8.05 Ni in mineral spirits) were purchased from Alfa Aesar and dried under high vacuum for 12 hours prior to use. HSi(OEt)3 was acquired from Momentive Performance Materials and were distilled from calcium hydride before use. DSi(OEt)32 was prepared according to literature procedures. N,N’-Bis(2,6-diisopropylphenyl)-2,3-

butanediimine

according to literature procedures.3

(iPrDI)

and

iPr

DINiBr2

were

prepared

Ethylenebis(diphenylphosphine) (dppe), N,N,N′,N′-

Tetramethylethylenediamine (tmeda), 2,2′-Bipyridyl (bpy), neocuproine (neo), and (4R,4'R)-2,2'(propane-2,2-diyl)bis(4-isopropyl-4,5-dihydrooxazole) (iPrBOX) were purchased from Sigma Aldrich and dried under high vacuum prior to use. N-(2,6-diisopropylphenyl)-1-(pyridin-2yl)ethan-1-imine

(iPrPI)4,

N-cyclohexyl-1-(pyridin-2-yl)ethan-1-imine

(cyAPI)4,

N,N-bis(2,6-

diisopropylphenyl)ethane-1,2-diimine (iPrDAI)5, N,N-bis(2,6-diisopropylphenyl)acenaphthylene1,2-diimine

(iPrBIAN)6,

N,

N-dicyclohexylbutane-2,3-diimine

4,4',5,5'-tetrahydro-2,2'-bioxazole ethylethanamine)

(EtNNN)9,

(MeBiOX)8,

(cyADI)7,

4,4,4',4'-tetramethyl-

N,N'-(pyridine-2,6-diylbis(methylene))bis(N-

1,1'-(pyridine-2,6-diyl)bis(N-(2,6-diisopropylphenyl)ethan-1-imine)

(iPrPDI)10, and 1,1'-(pyridine-2,6-diyl)bis(N-methylethan-1-imine) (MeAPDI)11 were prepared according to literature procedures.

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1

H NMR spectra were recorded on Bruker AVANCE 300, Varian Inova 400 and Bruker

AVANCE 500 spectrometers operating at 300.13, 399.78 and 500.62 MHz respectively.

13

C

NMR spectra were recorded on a Bruker AVANCE 500 operating at 125.89 MHz. All 1H and

13

C

chemical shifts are reported relative to SiMe4 using the 1H (residual) and

13

C chemical shifts of

the solvent as a secondary standard. UV-visible absorption spectra were recorded on an Agilent 8453 diode array UV/Vis spectrophotometer. Samples were charged into a sealable quartz cuvette under a nitrogen atmosphere and quickly transferred to the spectrometer to record their absorption spectra. Gas chromatography-mass spectrometry (GC-MS) was performed on an Agilent 6890 GC-5975C MSD equipped with a Gerstel AOC-5000 autosampler and using a HP-5MS column (30 meters, 0.25mm, 0.25 μm film) at 1.0 mL/min. All DFT calculations were performed with the ORCA program package in the gas phase.12 The geometry optimizations of the complexes and single-point calculations on the optimized geometries were carried out at the B3LYP level of DFT.13 The all-electron Gaussian basis sets were those developed by the Ahlrichs group.14 Triple-ζ quality basis sets def2-TZVP with one set of polarization functions on nickel and nitrogen were used. For the carbon and hydrogen atoms, slightly smaller polarized split-valence def2-SV(P) basis sets were used that were of double-ζ quality in the valence region and contained a polarizing set of d functions on the non-hydrogen atoms. Auxiliary basis sets to expand the electron density in the resolution-ofthe-identity (RIJCOSX)15 approach were chosen to match the orbital basis.16

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II. Full Ligand Screen for the Ni-catalyzed Hydrosilylation of 1-octene.

General Procedure: In a N2-filled glovebox, a scintillation vial was charged with a magnetic stir bar, 0.064 g (0.089 mmol, 8.05% Ni) of Ni(2-EH)2, 0.089 mmol of ligand, 0.292 g (1.78 mmol) of HSi(OEt)3, and 0.200 g (1.78 mmol) of 1-octene. The resulting mixture was stirred for 12 hours. An aliquot of the crude mixture was taken to determine the conversion of the 1-octene by gas chromatography. The reaction was then exposed to air and passed through a plug of silica using 5% Et2O / pentane as the eluent. Following solvent removal, a colorless to pale yellow liquid was recovered which was analyzed by 1H NMR and

13

C NMR and weighed to determine the

isolated yield. The ratio of Product A : Product B was determined by integration of the 1H spectra. Product A: 1H NMR (500 MHz, CDCl3) δ = 0.61 (m, 2H), 0.85 (t, 3H, 6.4 Hz), 1.20 (t, 9H, 7.1 Hz), 1.24 (m, 10H), 1.39 (m, 2H), 3.78 (q, 6H, 7.5 Hz). Product B: 1H NMR (500 MHz, CDCl3): δ = 0.88 (t, 3H, CH3), 1.19 (t, 9H, OCH2CH3), 1.26 (m, 2H, CH2), 1.26 (m, 2H, CH2), 1.36 (m, 2H, CH2), 1.74 (d, 2H, CH2 – E isomer), 1.78 (d, 2H, CH2 – Z isomer), 2.02 (m, 2H, CH2 – E isomer), 2.13 (m, 2H, CH2 – Z isomer), 3.83 (q, 6H, OCH2CH3) 5.45 (m, 1H, CH – E isomer), 5.49 (m, 1H, CH – Z isomer), 5.66 (m, 1H, CH – E isomer), 5.69 (m, 1H, CH – Z isomer).

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npent

+ (OEt) 3SiH

5 mol% Ni(O 2CC7H15) 2 5 mol% Ligand 23 °C, neat, 12 hr

Entry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Ph

Ph

npent

Si(OEt)3 A +

npent

Si(OEt)3 B % Isolated Yield (A:B) 43 (69:31) 37 (37:63) 0 (N/A) 31 (92:7) 38 (85:14) 71 (92:8) 40 (97:3) 78 (99:1) 68 (89:11) 59 (100:0) 65 (93:7) 33 (49:50) 43 (86:14) 0 (N/A) 29 (70:27) 58 (100:0)

Ligand none dppe tmeda bpy neo iPrPI cy API iPrDI iPrDAI iPrBIAN cy ADI MeBiOX iPrBOX EtNNN iPrPDI Me APDI

Ph P

N

N

N

P

N

N

N

N N iPr

Ph

dppe

tmeda

Ar

Ar N

N

iPrBIAN

N

N

N

O

iPr

iPr

O

cy ADI

MeBiOX

iPr

iPr

iPrDAI Ar

N

Et

N

N N N

N

N

iPrDI

N

N

N iPr

O

iPr

Et

iPr

O

N

iPr

cy API

iPrPI

Ar N

N

N iPr

neo

bpy

N

Ar N

iPrBOX

Et

iPr

iPr

N

N

Et

EtNNN

iPrPDI

Me APDI

Figure S1: Results of Nickel-Catalyzed Hydrosilylation as a Function of Various Ligands.

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III. Preparation of Nickel Complexes.

(iPrDINiH)2 (Method 1). A 100 mL round bottom flask was charged with 2.50 g (4.01 mmol) of iPr

DiNIBr2 and 50 mL of Et2O. To the vigorously stirring solution was added 8.42 mL (8.42 mmol)

of NaHB(Et)3 (1 M in toluene) over 5 minutes. The solution immediately changed color from pale orange to deep purple. The reaction mixture was stirred for an additional 5 days. The solution was filtered through a pad of celite and the volitiles were removed in vacuo yielding a purple oil. The oil was successively treated with an aliquot of pentane followed by rapid solvent evaporation (5 x 5 mL). The resulting purple residue was dissolved in 50 mL of pentane and filtered through a pad of celite to remove residual solids. The volatiles of the filtrate were removed in vacuo yielding a purple solid. The solid was dissolved in 10 mL of tetramethylsilane and cooled to -35 °C inducing the precipitation of a purple solid mass. The solid was collected on a fine frit. This procedure yielded 0.790 g (0.851 mmol, 42 % yield) of (iPrDINi-H)2. 1H NMR (500 MHz, C6D6, 23 °C) δ = -15.79 (s, 2H, Ni-H), 1.09 (d, 24H, 6.8 Hz, (CH3)2CH-Ar), 1.67 (d, 24H, 6.5 Hz, (CH3)2CH-Ar), 3.73 (bs, 6H, CH3(C=N)), 3.87 (sept, 8H, 6.7 Hz, (CH3)2CH-Ar), 6.48 (t, 4H, 7.4 Hz, p-Ar-CH), 7.95 (d, 8H, 7.4 Hz, m-Ar-CH). 13C NMR (126 MHz, C6D6, 23 °C) δ = 12.8 (CH3(C=N)), 25.0 ((CH3)2CH-Ar), 26.2 ((CH3)2CH-Ar), 27.0 ((CH3)2CH-Ar), 121.0 (p-Ar-CH), 129.6 (m-Ar-CH), 148.1 ((CH3)2CH-C(Ar)), 159.4 ((C=N)-C(Ar, ipso)). One resonance not located ((C=N)). UV/Vis (toluene, 23 °C): 515 nm (3,225 M-1cm-1).

(iPrDINiH)2 (Method 2). A 100 mL round bottom flask was charged with 2.72 g (3.70 mmol) of Ni(2-EH)2 (% 8.05 Ni in mineral spirits), 1.50 g (3.70 mmol) of

iPr

DI, and 50 mL of pentane. To

the vigorously stirring solution was added 3.65 g (22.2 mmol) of HSi(OEt)3 over 5 minutes. The reaction mixture was allowed to stir at room temperature for 12 hours. During this reaction

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period, a color change from pale yellow to deep purple was observed. The volatiles were removed in vacuo yielding a purple oil. The oil was dissolved in 50 mL of tetramethylsilane, cooled to a cold slush, and the thawing solution was passed through a fine frit. A purple solid was collected and identified as (iPrDINi-H)2 based on 1H NMR, 13C NMR, and UV/Vis spectroscopy. This procedure yielded 0.412 g (0.444 mmol, 24 % yield) of (iPrDINi-H)2. Single crystals were obtained by dissolution of the purple solid in a minimal volume of Et2O followed by slow evaporation at -35 °C over a period of 5 days. The unit cell matched that of (iPrDINi-H)2 ( a = b = 28.625 Å, c = 13.206 Å, α = β = 90°, γ = 120°). NMR Spectra of (iPrDINiH)2.

Figure S2: 1H NMR spectrum (500 MHz, 23 °C) of [iPrDINiH]2 in C6D6 solution.

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Figure S3: 13C NMR spectrum (126 MHz, 23 °C) of [iPrDINIH]2 in C6D6 solution. IV. Nickel-Catalyzed Alkene Hydrosilylation Using Ni(2-EH)2.

General Procedure. In a N2-filled glovebox, a scintillation vial was charged with a magnetic stir bar, 0.013 g (0.018 mmol, 8.05% Ni) of Ni(2-EH)2, 0.007 g (0.018 mmol) of

iPr

DI, and 0.018 g

(0.3108 mmol) of (EtO)3SiH. To this vial was added 0.198 g (1.77 mmol) of 1-octene followed by 1.77 mmol of the silane. The resulting mixture was stirred for 6 hours. A deep blue color evolved after 1 hour. An aliquot of the crude mixture was taken to determine the conversion of the starting material by gas chromatography. The reaction was then exposed to air and passed through a plug of silica using 5% Et2O / pentane as the eluent. Following solvent removal, a colorless to pale yellow liquid was recovered which was analyzed by 1H NMR and weighed to determine the isolated yield.

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13

C NMR and

Product Characterization.

hex hex

Si(OEt)3 1 SiMe(OSiMe3) 2 4

hex hex

SiMe(OEt)2 2

hex

SiMe2(OEt) 3

SiMe2(OSiMe 3) 5

Figure S4: Products of Ni-catalyzed hydrofunctionalization and the corresponding labels used in this text. 1: The title compound was isolated as a colorless oil (0.476 g, 97%). 1H NMR (500 MHz, CDCl3) δ = 3.78 (q, 6H, 7.5 Hz), 1.39 (m, 2H), 1.24 (m, 10H), 1.20 (t, 9H, 7.1 Hz), 0.85 (t, 3H, 6.4 Hz), 0.61 (m, 2H). 13C NMR (126 MHz, CDCl3) δ = 58.4, 33.3, 32.0, 39.8, 29.4, 22.9, 22.8, 18.4, 14.2, 10.5. 1H and 13C NMR data agree with previously reported data.17 2: The title compound was isolated as a colorless oil (0.376 g, 86%). 1H NMR (500 MHz, CDCl3): δ = 3.75 (4H, q, J = 7.0 Hz), 1.39-1.18 (12H, m), 1.21 (6H, t, J = 7.0 Hz), 0.87 (3H, t, J = 7.1 Hz), 0.64-0.57 (2H, m), 0.10 (3H, s). 13C NMR (125 MHz, CDCl3): δ = 58.2, 33.5, 32.1, 29.43, 29.38, 23.0, 22.8, 18.6, 14.3, 14.0, -4.7. 1H and 13C NMR data agree with previously reported data. 3: The title compound was isolated as a colorless oil (0.357 g, 93%). 1H NMR (500 MHz, CDCl3): δ = 3.65 (2H, q, J = 7.0 Hz), 1.36-1.22 (12H, m), 1.18 (3H, t, J = 7.0 Hz), 0.88 (3H, t, J = 7.1 Hz), 0.62-0.54 (2H, m), 0.09 (6H, s). 13C NMR (125 MHz, CDCl3): δ = 58.3, 33.6, 32.1, 29.5, 29.4, 23.4, 22.8, 18.7, 16.5, 14.3, -1.9. 1H and 13C NMR data agree with previously reported data. 4: The title compound was isolated as a colorless oil (0.591 g, 99%). 1H NMR (500 MHz, CDCl3): δ = 1.34-1.22 (12H, m), 0.88 (3H, t, J = 7.1 Hz), 0.48-0.41 (2H, m), 0.08 (18H, s), -0.01 (3H, s). 13C NMR (125 MHz, CDCl3): δ = 33.4, 32.1, 29.5, 29.4, 23.2, 22.9, 17.8, 14.3, 2.0, -0.1.

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1

H and 13C NMR data agree with previously reported data.

5: The title compound was isolated as a colorless oil (0.412 g, 90%).1H NMR (500 MHz, CDCl3): δ = 1.34-1.22 (12H, m), 0.88 (3H, t, J = 7.1 Hz), 0.53-0.47 (2H, m), 0.06 (9H, s), 0.03 (6H, s). 13

C NMR (125 MHz, CDCl3): δ = 33.6, 32.1, 29.5, 29.4, 23.4, 22.9, 18.5, 14.3, 2.1, 0.5. 1H and

13

C NMR data agree with previously reported data.

V. Deuterium Labeling Experiments

Hydrosilylation of 1-octene with DSi(OEt)3. In an N2-filled glovebox, a scintillation vial was charged with a magnetic stir bar, 0.198 g (1.77 mmol) of 1-octene, 0.292 g (1.77 mmol) of DSi(OEt)3, and 0.016 g (0.0177 mmol) of [iPrDINiH]2. The blue reaction mixture was stirred for 12 hours. An aliquot of the reaction was dissolved in C6H6 and analyzed by 2H NMR to determine the amount of deuterium incorporation into each position of the product.

Figure S5: Deuterium incorporation studies. 2H % values have been normalized to account for the number of hydrogen atoms at each position. A statistical distribution would yield 12.5 % 2H at each position. Key for 2H NMR: experimental spectrum (black), fit spectrum (blue), residuals (red).

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VI. Procedure for the Method of Continuous Variations.

Reaction of Ni(2-EH)2 and HSi(OEt)3. In an N2-filled glovebox, eleven samples were prepared in 20mL scintillation vials by combining an appropriate amount of HSi(OEt)3,

iPr

DI, Ni(2-EH)2, and

diluting the mixture volumetrically to a total volume of 2 mL. The total concentration of Ni(2-EH)2 and HSi(OEt)3 was held constant at 0.100 mmol. Each solution contained an equimolar amount of

iPr

DI and Ni(2-EH)2. The solutions were stirred at room temperature for 6 hours while the color

was observed to change from pale yellow to deep blue. A quartz cuvette was charged with an aliquot of each solution, sealed, and the UV/Visible spectrum was measured. The absorbance at 515 nm was recorded for each sample followed by baseline correction and normalization.

Figure S6: Method of continuous variations to determine the optimal amount of (EtO)3SiH for activation of (iPrDI) / Ni(2-EH)2 mixtures. Dashed line shows a qualitative fit of the data.

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Table S1: Data for the Method of Continuous Variations using (EtO)3SiH as the Reducing Agent iPr

Ni(2-EH)2 (mmol)

DI (mmol)

HSi(OEt)3 (mmol)

Mol Fraction χHSi(OEt)3

Normalized Absorbance (λ =515 nm)

91.7

Molar Ratio HSi(OEt)3 / Ni(2-EH)2 11

8.33

8.33

0.917

9.09

0.766

9.09

90.9

10

0.909

0.807

10

10

90.0

9

0.900

0.865

11.1

11.1

88.9

8

0.889

0.934

12.5

12.5

87.5

7

0.875

0.981

14.3

14.3

85.7

6

0.857

1.00

16.7

16.7

83.3

5

0.833

0.871

20.0

20.0

80.0

4

0.800

0.622

25.0

25.0

75.0

3

0.750

0.414

33.3

33.3

66.7

2

0.667

50.0

50.0

500

1

0.500

0.176 0.00

Figure S7: UV/Visible absorption spectra at various ratios of HSi(OEt)3 : Ni(2-EH)2 in the presence of iPrDI.

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VII. Quantification of H2(g) generation.

Reaction of Ni(2-EH)2 and HSi(OEt)3. In an N2-filled glovebox, 0.147g (0.200 mmol) Ni(2-EH)2, 0.081g (0.20 mmol)

iPr

DI, and 10 mL toluene were combined in a thick walled glass ampule and

sealed. 0.196 g (1.20 mmol) of HSi(OEt)3 was added to a separate thick walled glass ampule and sealed. Both vessels were subjected to five freeze-pump-thaw cycles on a high vacuum line in order to ensure that they were rigorously degassed. The HSi(OEt)3 was vacuum-transferred to the solution containing

iPr

DI and Ni(2-EH)2 and the resulting mixture was stirred at room

temperature for 4 hours. During this period of time, a color change from pale yellow to deep blue was observed. Using a Toepler pump, 0.089 mmol (84 mmHg, 19.8 mL, 298 K; 0.445 equivalents per Ni ) of gas was collected. The gas was passed over a bed of CuO heated to 200 °C. After this procedure, no gas was collected.

iPrDI

Amount (mmol):

0.20

+ Ni(C 8H15 O 2) 2 + 6 HSi(OEt) 3 0.20

1.2

Toluene, 3hr, rt -1/2 [iPrDiNi-H] 2

1/2 H 2 0.089a

Figure S8: Results of Toepler pump experiments to quantify the formation of H2. aThis quantity of gas reacted with CuO. iPrDI + Ni(C H O ) + 4 HBPin 1/2 H 2 8 15 2 2 Toluene, 3hr, rt -1/2 [iPrDiNi-H] 2 Amount (mmol): 0.087a 0.20 0.20 0.80

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VIII. Beer’s Law Plot of [iPrDINi-H]2

Figure S9: Beer’s Law plot of [iPrDINi-H]2 in toluene at 23 °C.

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IX. Characterization of the Products of in situ Activation by HSi(OEt)3

Figure S10: Silicon-containing products upon treatment of Ni(2-ethylhexanoate)2 with HSi(OEt)3 (in-situ activation procedure) as determined by GC/MS and decomposition experiments.

Figure S11: GC chromatogram and selected mass spectra (MS) of the crude reaction mixture upon treatment of Ni(2-ethylhexanoate)2 with iPrDI and 6 equivalents of HSi(OEt)3 (cf. Figure S8) Experimental MS are shown in black. MS of reference compounds are shown in red.

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Figure S12: GC chromatogram and selected mass spectra of the reaction mixture upon treatment of Ni(2-ethylhexanoate)2 with iPrDI and 6 equivalents of HSi(OEt)3 followed by hydrolysis with H2O. (cf. Figure S8) Experimental MS are shown in black. MS of the reference compound is shown in red.

X. 10-gram Scale Hydrosilylation. CAUTION! Alkene hydrosilylation reactions are exothermic. The following procedure should be performed with appropriate protective equipment and a ready ice bath in case of a violent exotherm. Method 1 (0.1 mol% catalyst loading): In an N2-filled glovebox, a 50 mL round bottom flask was charged with 5.86 g (35.65 mmol) of HSi(OEt)3 and 4.00 g (35.65 mmol) of 1-octene. Separately, a scintillation vial was charged with 0.026 g of Ni(2-EH)2 (8.05 % Ni, 0.035 mmol) and 0.014 g

iPr

DI (0.035 mmol). 0.200 mL of the HSi(OEt)3 / 1-octene solution was added to the

scintillation vial containing the mixture of Ni(2-EH)2 and

iPr

DI. After 10 minutes, a deep blue color

evolved. The catalyst solution was loaded into a 1 mL syringe and reserved.

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The 50 mL round bottom flask was removed from the glove box and outfitted with a reflux condenser, Ar inlet, and two rubber septa. The flask was placed in an oil bath with a temperature probe to control the reaction temperature and stirred vigorously. The reserved catalyst solution was injected into the reaction flask in one portion. The reaction vessel was heated to 40 °C for 6 hours. During this period of time, a persistent deep blue color was observed. At the termination of the reaction, the vessel was exposed to air and the deep blue color immediately gave way to a colorless solution. Analysis of the reaction mixture by GC indicated > 99 % conversion of the starting material. The exclusive formation of noctyl-Si(OEt)3 was confirmed by

1

H NMR. The reaction mixture was passed through a plug of silica,

transferred to a clean vessel, and weighed yielding 9.47 g (96 % yield) of a colorless oil.

Figure S13: Reaction apparatus for the 10-gram scale hydrosilylation of 1-octene with HSi(OEt)3 using substrate-activated Ni catalysis via method 1. (a) Reaction mixture prior to the injection of the catalyst solution. (b) Reaction mixture after injection of the catalyst solution and heating to 40 °C for 1 hour. Method 2 (0.5 mol% catalyst loading): A 50 mL 3-neck round bottom flask was outfitted with a reflux condenser, Ar inlet, two rubber septa, and magnetic stir bar. The flask was placed in an oil bath with a temperature probe. The reaction vessel was purged with Ar for 10 minutes. Using

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a syringe, 4.00 g (35.65 mmol) of 1-octene was added against the Ar purge. Next, 0.13 g of Ni(2EH)2 (8.05 % Ni, 0.175 mmol) and 0.07 g

iPr

DI (0.175 mmol) were added sequentially against the

Ar purge. The reaction was stirred vigorously and purged with Ar for an additional 10 minutes. 5.86 g (35.65 mmol) of HSi(OEt)3 was added as one portion. After 5 minutes, a deep blue color evolved. The reaction vessel was heated to 40 °C for 6 hours. During this period of time, a persistent deep blue color was observed. At the termination of the reaction, the vessel was exposed to air and the deep blue color immediately gave way to a colorless solution. Analysis of the reaction mixture by GC indicated > 99 % conversion of the starting material. The exclusive formation of noctyl-Si(OEt)3 was confirmed by 1H NMR. The reaction mixture was passed through a plug of silica, transferred to a clean vessel, and weighed yielding 9.57 g (97 % yield) of a colorless oil.

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XI. Silicone Fluid Crosslinking. A scintillation vial was charged with 5.0 g of MviD120Mvi (SL6100) in which Mvi is vinyl dimethyl SiO, and 0.22 g of MD15Dʼ30M. In a second vial, a stock solution of the catalyst was prepared by dissolving 0.012 g (8.05 % Ni, 0.016 mmol 0.97 mg Ni) of Ni(2-EH)2, 0.006 g (0.016 mmol) of

iPr

DI, and 0.016 g (0.096 mmol) of HSi(OEt)3 in 0.100 g of toluene. 0.050 g of the

catalyst solution (97 ppm Ni) was added to a mixture of MviD120Mvi and MD15Dʼ30M. The scintillation vial was sealed and placed in an oil bath at 80 °C. After 2 hours, the mixture was bright blue and viscous. Upon cooling, formation of a solid gel was observed. Exposure of the gel to air caused a color change from blue to colorless.

A

B

C

D

E

Figure S14: Silicone fluid crosslinking using nickel catalysis. (a) Crosslinked silicone polymer before exposure to air. (b) 30 min after exposure to air (c) 1hr after exposure to air (d) 2hr after exposure to air (e) Crosslinked silicone polymer after grinding (left) and intact gel (right).

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XII. Kinetics Data General Procedure: In a N2-filled glovebox, a 5 mL volumetric flask was charged with the appropriate volumes of 1-octene (5.0 M in hexane), (EtO)3SiH (5.0 M in hexane), (iPrDiNiH)2 (0.1 M in hexane), mesitylene (2.5 mmol), and diluted to 5 mL with hexane. The solution was rapidly transferred to a 20 mL scintillation vial equipped with a stir bar. Aliquots (~10 uL) were removed from the reaction at 2-5 min intervals, immediately diluted, and removed from the glove box. The yield of nOctylSi(OEt)3 was determined by gas chromatography after comparison to the internal mesitylene standard. Table S2: Method of initial rate to determine the rate law Trial

[1-octene] M

[(EtO)3SiH] M

[(iPrDINiH)2] M

1

0.5

0.5

5 x 10

2 3 4 5 6 7

1

0.5

0.5 0.25 0.5 0.5 0.5

1 0.5 0.25 0.5 0.5

5 x 10 5 x 10 5 x 10 5 x 10

-3 -3 -3 -3 -3

2.5 x 10 1 x 10

-3

-2

Initial Rate Ms-1 2.0 x 10 3.6 x 10 4.2 x 10 9.9 x 10 9.2 x 10 1.3 x 10 2.6 x 10

-4

0.01148 -4

0.01024

-4

0.01196 -5

0.01123 -5

0.01040 -4

0.01048 -4

Order in (EtO)3SiH: 1.10 ± 0.03 Order in 1-octene: 0.93 ± 0.06 Order in (iPrDiNiH)2: 0.48 ± 0.09 Rate = kobs [(iPrDINiH)2]1/2 [1-octene] [(EtO)3SiH] kobs = 0.0109 ± 0.0006 M-1.5s-1

S21

k (M-1.5s-1)

0.01024

Figure S15: Kinetic data for the formation of nOctylSi(OEt)3 as a function of time for various reaction trials. See Table S2 for the key.

Figure S16: Kinetic data for the formation of nOctylSi(OEt)3 as a function of time for various reaction trials. See Table S2 for the key. Error in Reaction order determined by regression analysis.

S22

Figure S17: Kinetic data for the formation of nOctylSi(OEt)3 as a function of time for various reaction trials. See Table S2 for the key. Error in Reaction order determined by regression analysis.

Figure S18: Kinetic data for the formation of nOctylSi(OEt)3 as a function of time for various reaction trials. See Table S2 for the key. Error in Reaction order determined by regression analysis.

S23

XIII. DFT Calculations.

DFT Input File Example ! UKS B3LYP RIJCOSX def2-SVP def2-SVP/J Normalprint SlowConv TightSCF Opt Pal8 UCO %basis NewGTO 28 "def2-TZVP(-f)" end NewGTO 7 "def2-TZVP(-f)" end NewAuxGTO 28 "def2-TZVP/J" end NewAuxGTO 7 "def2-TZVP/J" end end %SCF MaxIter 500 TolE 1e-7 TolErr 1e-6 end * xyz 0 # xyz coordinates *

S24

Qualitative Molecular Orbital Diagram of iPrDINiH.

Figure S19: (a) DFT-computed qualitative molecular orbital diagram for iPrDINiH. (b) DFT computed spin density plot for iPrDINiH.

S25

Qualitative Molecular Orbital Diagram of iPrDINi(n-octyl).

Figure S20: (a) DFT-computed qualitative molecular orbital diagram for iPrDINi(n-octyl). (b) DFT computed spin density plot for iPrDINi(n-octyl).

S26

Optimized Geometry of iPrDINiH. Ni N N C C C H H H C H H H C C C H C H C H C C H C H H H C H H H C H C H H H C H H H C C

-0.05054417525972 1.89384689759013 -0.03233352644493 2.26394618853276 1.18133490455326 3.69202722541657 3.87326718079646 3.93738619770221 4.39284680587759 1.46819364713243 0.54184108830943 2.02670965292517 2.09026166980348 2.83259580076859 3.39822568610775 4.29884343133470 4.74238333657426 4.63307446960841 5.34218299412388 4.04144778889064 4.29310239307628 3.12655425230611 3.01185930293790 2.38242552971058 2.15148411280553 1.27526214771107 1.78219326616754 2.73077537019486 4.22719236134698 4.84700886369981 3.89334023467446 4.87514295115560 2.47031128303982 1.70481806201634 1.74750037273395 2.45342982445964 1.17776262081574 1.04182287265420 3.47095901531189 4.25222381292045 3.97538710949168 2.95635958284981 -1.21497081711144 -1.70866106428610

-0.00867199954354 0.25677982270463 1.96114551556531 1.49337411004904 2.45135215820999 1.92583232655731 2.25062409066107 2.78616182667895 1.11392794011590 3.89064647627787 4.45597864807434 4.38249182025202 3.98001590402816 -0.80924605632811 -1.43764842463829 -2.49313814934394 -2.99253738644811 -2.92557000111930 -3.74628732359328 -2.31765037603354 -2.67259087288732 -1.26591829264894 -1.03683454331547 -0.13846728986955 -2.12795572758841 -2.37222476060054 -1.78646537459775 -3.05277563965557 -0.67619234594338 -1.55999460410809 -0.25510012188777 0.06732900607732 -0.63539241946829 0.06380430090107 -1.67537401039464 -2.37043311995700 -1.17384685319582 -2.27855842570489 0.18862489173776 -0.45376044481602 0.94954428597965 0.70711367856737 2.75349899101398 3.45892024500138

-0.02514045607092 -0.21337597598205 0.02024864470690 0.07683163031963 0.21015603143815 0.27482853042340 1.31415512347621 -0.36823892119258 0.04484326045539 0.54519454100659 0.70488907051666 -0.26936595014912 1.45119810117611 -0.36468065160335 0.77429826441234 0.56745931949986 1.43203032971069 -0.71580408939255 -0.85467695227387 -1.82280069146420 -2.82607960281712 -1.67352868742430 2.19678889538862 2.13088106719941 2.85908714616546 2.23960796498482 3.84086447660636 3.01806776041833 3.06915281596861 3.29560757515181 4.03228182196912 2.57817146825625 -2.89907727137425 -2.53062300418536 -3.77277179764196 -4.25775166869531 -4.57283141016959 -3.17879566220106 -3.72883471816483 -4.16875148105888 -3.11194139888981 -4.55527447356714 0.14101481440109 -0.98501490411553

S27

C H C H C H C C H C H H H C H H H C H C H H H C H H H H

-2.92195553399593 -3.32447946939531 -3.62163261915611 -4.56404847094291 -3.11204035643121 -3.65887926530697 -1.91639014365913 -0.95737199563234 -0.04338291190505 -1.76944139736212 -2.07099181112119 -1.17530121858684 -2.68767175006499 -0.52701277966073 0.09683658433862 0.05093883181022 -1.40090163816321 -1.37834365519794 -0.55042812415012 -0.80791956558525 -0.05072602771720 -0.33278895638424 -1.59980701147830 -2.41134803354482 -3.26151553709822 -1.93776344849973 -2.80400006798911 -0.78976435214561

4.15135469668691 -0.85218656933045 4.69500486894666 -1.71116695474780 4.16739844286405 0.35346300790443 4.71475077765082 0.43553957845257 3.48122858259050 1.45562286352292 3.50670574978591 2.40168857094352 2.75418981592515 1.37483719268466 3.49226371701160 -2.31565956407525 2.89273841966153 -2.19321473437705 2.85019497343089 -3.45416398233955 1.82019362970499 -3.20538465257446 2.81916161992920 -4.38296520613069 3.42178516278110 -3.66831509969537 4.92417689075413 -2.69409760025853 4.91919047818751 -3.60356815572444 5.40330953079311 -1.88819995317342 5.56450550590956 -2.89905265718035 2.02375092313693 2.60433904934785 1.38284399967521 2.26955110753249 3.01379971745700 3.63593630492546 3.67503287960594 3.18557477702837 2.47469434732002 4.47269152290118 3.65519664557507 4.05802027009463 1.08603891660564 3.24713699692110 1.63683819795685 3.68341839162896 0.51169276680438 4.06079732829218 0.36382425765548 2.51528698728307 -1.04252698917171 0.87331229492597

Optimized Geometry of iPrDINi(n-octyl). Ni N N C C C H H H C H H H C C

0.01887243045796 0.26482040656558 1.60026226688225 1.41923643861006 2.16707685712761 1.95983844177529 2.76200531697761 2.40151679058236 1.17340349697271 3.50025076647441 3.86569433189294 3.44009410151283 4.26230625897543 -0.57017311480937 -0.28932004206962

1.00831613849773 2.85269605970523 0.70234547113920 3.03632681908334 1.83019232558500 4.38972518319665 4.71282484444202 4.37683909987261 5.15547368090359 1.89912432788299 0.89917634013834 2.49745895659703 2.38094239878644 3.95516610067297 4.70549718478617

S28

-0.24220412940734 0.40801848632715 0.92360730051230 1.04063496382363 1.32628390641260 1.42351232897643 0.73576163329664 2.43150722043489 1.39900237664946 2.02588344588766 2.29133671873796 2.94873250821641 1.38855736835251 0.04777244034567 -1.12420274501878

C H C H C H C C H C H H H C H H H C H C H H H C H H H C C C H C H C H C C H C H H H C H H H C H C

-1.13908845147726 -0.93755760416070 -2.23802888852073 -2.88344301272424 -2.51923082543353 -3.39235242606152 -1.70601284319191 0.85720860764667 1.45219648135742 0.31384585714432 -0.32712803834626 1.14096376286022 -0.28231309858111 1.80332550536232 1.29756923851074 2.65386378603357 2.20567240960088 -2.09031140633956 -1.28681379617021 -3.38188745805139 -4.24387085606701 -3.61656771456360 -3.28941833567847 -2.22687544433106 -3.02210917065939 -1.29145417666290 -2.48594308630210 2.21176710192322 1.73829495445486 2.30188425304235 1.95143973016975 3.30848010684682 3.74287367133194 3.75777545068798 4.54146226845647 3.22368366813723 0.63317585741844 0.64880243254340 -0.76259844680881 -0.94764560966900 -1.55018132832216 -0.86863230026887 0.84495805166535 0.12549283973856 1.85881406068522 0.68457243631232 3.72774974510492 3.16780835671581 5.22614627023947

5.77361715153676 6.36289355772969 6.09719319514178 6.93771837408045 5.32947487697577 5.57542540748765 4.24783594357651 4.34330914735153 3.55644014489046 3.75039347998737 2.87676949880879 3.42611841366908 4.49389707490196 5.52283444877785 6.32918175768848 5.18556136103609 5.96205346674474 3.39600842607942 2.66147216704246 2.60168291747905 3.27548992175075 1.92398162912109 1.99130820410939 4.21760364577285 4.97720731516431 4.74378096936302 3.55996030268602 -0.57216070082332 -1.38309858399256 -2.65532217067795 -3.29686601159852 -3.11939932064233 -4.11016767287603 -2.31486614939513 -2.68782876985378 -1.03553110706069 -0.89205322427531 0.20782385344632 -1.34255318740664 -1.06350271746025 -0.87920850466886 -2.43773221266600 -1.29704241450226 -0.77062815223640 -1.04691647548823 -2.37675656577622 -0.20620772568106 0.73955520378677 0.13975478085204

S29

-1.44769021020045 -2.34575039307135 -0.65244375356311 -0.92103242314665 0.47702273570395 1.08802582514013 0.84607908643336 -2.06853180211899 -1.58385607178502 -3.38463319530158 -3.19455555384251 -4.03782265796248 -3.94087217627718 -2.35186561829301 -2.90837288227269 -2.96727928097090 -1.42496846468939 2.05441670867132 2.21236414257431 1.77482598281954 1.63826345662278 2.61257417007609 0.86251946067804 3.34794842635231 3.27050135131517 3.59942536958312 4.19468811257792 1.12715519606892 2.19307931546269 2.35932163555949 3.17067245869059 1.51157535460995 1.66884133966550 0.46642423390953 -0.19959363193201 0.24601181606524 3.12895565076507 3.09002713849803 2.65245886713283 1.60256545276994 3.26905856036277 2.73258682387302 4.59727683729006 5.24448850819971 4.94933235266956 4.75617366823657 -0.93602175793194 -0.93657004373010 -0.82602107718538

H H H C H H H C H C H H H C H C H H H C H C H H H C H C H H H H

5.47910125145403 5.51690015080558 5.85597341936985 3.44546490125946 4.03065952464659 3.72550525219116 2.38103386305278 -0.43543587431586 -1.28947466135221 -0.81905556926305 0.39326730467612 -1.66683917340203 0.01057123828804 -1.20024214508930 -2.01432168600056 -1.62860433276682 -0.34216384560350 -2.49594200798199 -0.82110697783478 -1.98632214954101 -2.78098134585946 -2.44429229487809 -1.11284110345971 -3.30691715617524 -1.64364418026959 -2.82856595349886 -3.63485617292313 -3.27557279493384 -1.97030133798089 -4.14176011581445 -2.46923993834678 -3.56980342197900

0.59760063839703 0.84903315261138 -0.75753852936260 -0.89738897195552 -1.82525418821955 -0.23323527740646 -1.15332049453631 0.10781566195564 0.66243442303409 -1.37315433405078 0.20780177174557 -1.46340592307890 -1.92758026797571 -2.10945586800317 -1.55786313321176 -3.56517354291617 -2.07746046692169 -3.58296645066161 -4.10194313846749 -4.33675231904106 -3.79506068641430 -5.77679204512570 -4.34831839790035 -5.76117860920184 -6.31939673630399 -6.56297450800680 -6.02491209515076 -7.99968144477529 -6.57544976628677 -8.01998631738619 -8.58150827833628 -8.53165375829286

0.14284023580289 -1.61871379937748 -0.94542726713045 -2.28376736212346 -2.38983429881325 -3.11896634837096 -2.39316039059053 -1.95326987096502 -2.39273575528524 -1.77548686372189 -2.67773039327936 -1.06919474954377 -1.29577331190148 -3.07333698397051 -3.58043416111572 -2.84686197442959 -3.77086393234045 -2.15952075504594 -2.31334254266263 -4.12205476440943 -4.66937110337009 -3.85684214897821 -4.80131714568648 -3.16356795153276 -3.31873129248766 -5.11541847459574 -5.64788347614025 -4.82462626221804 -5.81269605319109 -4.14114284245577 -4.34576766825553 -5.74428315946411

Optimized Geometry of iPrDINi(2-octyl). Ni N N C C C H H H C H H H C

-0.02906438135239 0.28442296563286 1.65380609899029 1.48204429118836 2.24463591173528 2.05430649034507 2.91946696010210 2.42328978965608 1.30810905363952 3.61339895371967 4.00970059657244 3.59150902522214 4.33722220229281 -0.56447432277910

0.82794789734692 2.76149878020235 0.66802071956848 3.00291486477244 1.83737354276405 4.38274407715325 4.56021272532766 4.51364471713190 5.16100599776470 1.98404358699184 1.01741499105056 2.66071266255789 2.41592669392034 3.81144130521275

S30

0.06173907862553 0.42281959718406 1.08693386394034 0.94141156133399 1.32307247430464 1.14082553890655 0.47885532894855 2.17098929876452 0.93746318807412 1.94038991603024 2.27581952312307 2.81037124349846 1.22704149302104 -0.03807965967610

C C H C H C H C C H C H H H C H H H C H C H H H C H H H C C C H C H C H C C H C H H H C H H H C H

-0.33317723614276 -1.20261530488015 -1.03669652325123 -2.27793146302140 -2.93856773774152 -2.51673862575408 -3.37373948531613 -1.68131087601283 0.78408490674623 1.32647030975320 0.21013619227126 -0.48991620094128 1.02042226538849 -0.32995229392131 1.80170746333490 1.33726355160147 2.62257638369202 2.24258749766907 -2.01432968742567 -1.20237388685001 -3.31405219397677 -4.17800535490516 -3.52791902922522 -3.24746406774312 -2.09209817912500 -2.89592563292954 -1.14951994316887 -2.30351342697515 2.28306193141528 1.82451628093806 2.39253792266138 2.05387676291750 3.39047592267196 3.82841526794878 3.83764124236046 4.62343079487427 3.30411330520338 0.73934600049842 0.75721884641207 -0.66691450775640 -0.88044928495010 -1.43974305443999 -0.77034755356912 0.98477079932848 0.28206253497047 2.00674558233262 0.82821422250310 3.80887570728139 3.53782528407054

4.42500359041641 5.44787178379705 5.93472930940600 5.85175228563632 6.65513683216050 5.20889369392111 5.51235038346752 4.17946654336671 3.97802023401272 3.15680906236555 3.41424434041030 2.58779145088444 3.03304459659376 4.18954845901577 5.09472801105208 5.92752805003273 4.70287773789271 5.51409366246366 3.45498403217998 2.73943597979275 2.63998224066168 3.29613421513121 2.07084762123162 1.92227001750329 4.39926058808493 5.14537539841543 4.95057911293559 3.82611896769427 -0.57498638082725 -1.30303465171451 -2.55887139396554 -3.13635514682394 -3.08192082498913 -4.05801621832661 -2.35014917283031 -2.76577791727668 -1.08855280805074 -0.73521212542272 0.35798474623988 -1.21679957924217 -1.00586717349433 -0.71412247865580 -2.30459090335772 -1.01957962735100 -0.44021300996229 -0.74383497773670 -2.08210921196726 -0.32024370351394 0.73595608564533

S31

-1.29828042224185 -1.70497760457154 -2.66926372432234 -0.91461009074466 -1.25155266799486 0.29958342235395 0.90758350915057 0.75536088349932 -2.24261993573617 -1.75243227772930 -3.55899056914483 -3.37137456312634 -4.20240530346222 -4.12834839275523 -2.54120183960481 -3.09527976800328 -3.16527620080520 -1.62356500370543 2.05766010147030 2.25239693265236 1.91104408516873 1.71437353166139 2.83154182844054 1.07839872541244 3.26810058376957 3.15574494777841 3.41866393995722 4.18691542629525 1.38873450275891 2.51715509569291 2.77145555304766 3.63426955503933 1.94917663911997 2.17364904462564 0.84970917117612 0.21371188519381 0.54617301259642 3.43136211364769 3.30202027057527 3.02227213859983 1.96092851699225 3.62607670674109 3.17485394767361 4.92154824598681 5.54134025176776 5.22820682226847 5.17213101007172 -0.67619650478473 -0.53890020233207

C H H H C H H H C C C H H H C H C H H H C H C H H H C H H H H H H

5.33815275280175 5.85444888020868 5.65510657897285 5.70346863638540 3.11182562293612 3.31138579431902 3.47955797753623 2.02190094806333 -0.87666664983054 -2.26169990371791 -0.95889048150393 -0.22303379320693 -1.74999804252668 -0.02478354415264 -1.24057551620487 -2.09393936935830 -1.53587919709162 -0.37673949463141 -2.42799163182867 -0.70832454665030 -1.76728222014756 -2.53328532215827 -2.20199215954569 -0.84566985327431 -3.12147310203198 -1.43750838285427 -2.44570711277928 -3.20773600925956 -1.52465427242625 -2.79705086385988 -2.76026327124847 -2.21023684046357 -2.95516467425765

-0.36508188617389 -0.07027608249313 0.32902528967998 -1.36504906638746 -0.78169290708463 -1.84755479128784 -0.19993519014713 -0.64372008481981 0.09455796346533 0.74363094542187 -1.44685295762296 0.42383572091972 -1.78686402571082 -1.90165126084362 -2.02914224604860 -1.49698013983921 -3.53239328582279 -1.81260790205976 -3.73745136504369 -4.08870743026668 -4.06953714189466 -3.44721087703864 -5.53719624287158 -3.93406994198907 -5.67101626124598 -6.17229870247330 -6.02326655316942 -5.40744932015976 -5.96464912852223 -7.06802481089680 0.41434994672173 1.84379109915925 0.48499434787773

S32

-0.83175058442376 0.09612742131382 -1.62675639545928 -1.11725474335886 -1.97093670248593 -2.17129747229719 -2.83267007320683 -1.90998030916016 -1.60029977661949 -1.79274458043276 -1.63622662425476 -2.43047069708554 -0.94018758486512 -1.25812281972729 -3.03586725865501 -3.49187418801195 -3.06691520848148 -3.69147891832635 -2.44529193627150 -2.58756758787656 -4.48483790523155 -4.98497601163850 -4.55604613405952 -5.08183912448605 -3.95680838576323 -4.07167427922886 -5.98783108578197 -6.49481858551666 -6.59271498742487 -6.01150155541363 -2.72683463714227 -1.83497395035010 -0.97187709447619

XIV. References. 1

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