Metal-Free Aromatic Hydrogenation: Aniline to Cyclohexylamine Derivatives

Transcription

1 Supplementary Data for: Metal-Free Aromatic Hydrogenation: Aniline to Cyclohexylamine Derivatives Tayseer Mahdi, Zachariah M. Heiden, Stefan Grimme* and Douglas W. Stephan* Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, CANADA M5S 3H6 Mulliken Center for Theoretical Chemistry, Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn, Beringstr. 4, D Bonn, Germany N-tert-butylaniline was synthesized by Pd catalyzed coupling reactions following the synthesis reported in the following paper Seo, H.; Roberts, B. P.; Abboud, K. A.; Merz, K. M.; Hong, Jr.; Hong, S., Org. Lett., 2010, 12, Synthesis of [tbunh 2 Ph][HB(C 6 F 5 ) 3 ] 1 In the glove box, a 100 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (100 mg, mmol) in pentane (7 ml). To the reaction tube N-tert-butylaniline (29.1 mg, mmol) was added, immediately resulting in a pale orange cloudy solution. The reaction tube was degassed three times through a freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After 10 min at R.T, a white precipitate was observed in the reaction vessel and the solution became clear and colourless. The tube was left to stir at R.T for 12 hrs. The solvent was decanted and the white precipitate was dissolved in minimum dichloromethane and precipitated with pentane. The product was washed with pentane (2 x 3 ml). Compound 4 was isolated in 82 % yield. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 7.15 (br s, 2H, NH 2 ), 7.12 (t, 1H, 3 J H-H = 7.3 Hz, p-ph), 7.06 (t, 2H, 3 J H-H = 7.3 Hz, m- Ph), 6.82 (d, 2H, 3 J H-H = 7.6 Hz, o-ph), 3.69 (br q, 1H, 1 J H-B = 78 Hz, BH), 1.02 (s, 9H, t Bu); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (br, 2F, o- C 6 F 5 ), (br, 1F, p-c 6 F 5 ), (br, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 78 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K) partial: δ (dm, 1 J C-F ~ 238 Hz, CF), (dm, 1 J C-F ~ 244 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (p-ph), (m-ph), (o-ph), 65.9 ( t Bu), 25.5 ( t Bu). Elemental analysis calcd (%) for C 28 H 17 BF 15 N: C 50.71; H 2.58; N 2.11; Found: C 50.27, H 2.87; N Synthesis of [tbunh 2 Cy][HB(C 6 F 5 ) 3 ] 2 In the glove box, a 25 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-tert-butylaniline (11.0 mg, mmol) in toluene (2 ml). Upon the addition of N-tert-butylaniline the solution became cloudy and orange. The reaction tube was degassed three times through a freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube

2 was placed in a 110 ºC oil bath, the mixture gradually became less cloudy and colourless. The reaction was allowed to proceed for 96 h. The toluene was then removed under reduced pressure resulting in crude pale yellow oil. The oil was washed with pentane (3 x 2 ml) affording the product as a white powder. Compound 2 was dried under vacuum and the product was isolated in 30 % yield. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 5.07 (br, 2H, NH 2 ), 3.55 (br q, 1H, 1 J B-H = 83 Hz, BH), 2.72 (m, 1H, N-Cy), 1.55 (m, 2H, Cy), 1.45 (m, 2H, Cy), 1.31 (m, 1H, Cy), 1.17 (m, 3H, Cy), 0.91 (s, 9H, t Bu), 0.90 (m, 2H, Cy); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (d, 2F, 3 J F-F = 23 Hz, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 83 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K) partial: δ (dm, 1 J C-F ~ 238 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), 61.0 ( t Bu), 56.1 (N-Cy), 31.9 (Cy), 25.8 ( t Bu), 24.4 (Cy), 23.6 (Cy). Elemental analysis calcd (%) for C 28 H 23 BF 15 N: C 50.25; H 3.46; N 2.09; Found: C 49.85, H 3.57; N Synthesis of [iprnh 2 Cy][HB(C 6 F 5 ) 3 ] 3 In the glove box, a 25 ml Teflon screw cap glass bomb equipped with a stir bar was charged with a solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-isopropylaniline (10.0 mg, mmol) in toluene (1 ml). The reaction tube was degassed three times through a freeze-pumpthaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. The reaction bomb was placed in a 110 ºC oil bath for 36 h. The toluene was removed under reduced vacuum to yield compound 3 as a white precipitate. The product was washed with pentane (2 x 2 ml) and dried under reduced pressure to give 93 % of 3. Crystals suitable for x-ray diffraction were grown from a layered dichloromethane / pentane solution at -40 ºC. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 5.10 (s, 2H, NH 2 ), 3.56 (q, 1H, 1 J H-B = 84 Hz, BH), 3.03 (m, 1H, 1 J H-H = 6 Hz, i Pr), 2.76 (m, 1H, N-Cy), 1.56 (m, 2H, Cy), 1.47 (m, 2H, Cy), 1.34 (m, 1H, Cy), (m, 5H, Cy), 0.91 (d, 6H, 1 J H-H = 6 Hz, i Pr); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 20 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 84 Hz, HB); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 238 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), 136.9(dm, 1 J C-F ~ 248 Hz, CF), (br, i- C 6 F 5 ), 56.7 (N-Cy), 49.8 ( i Pr), 29.4 (Cy), 24.1 (Cy), 24.0 (Cy), 18.9 ( i Pr). Elemental analysis calcd (%) for C 27 H 21 BF 15 N: C 49.49; H 3.23; N 2.14; Found: C 49.52, H 3.45; N Synthesis of [Cy 2 NH 2 ][HB(C 6 F 5 ) 3 ] 4 Method 1: In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-cyclohexyllaniline (13.0 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 36 h. The toluene was removed under reduced vacuum to yield compound 4 as a white precipitate. The product was washed with pentane (2 x 2 ml) and dried under reduced pressure to give 88 % of 4. Crystals suitable for x-ray diffraction were grown from a concentrated solution in C 6 D 5 Br at R.T Method 2: In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and diphenylamine (12.5 mg, mmol) in toluene (2 ml). Upon addition of diphenylamine, the solution became dark orange. The reaction tube was degassed three times through a freeze-pump-thaw cycle on the

3 vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. As the sample was frozen, the solution was observed to become colorless. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 96 h. The toluene was removed under reduced vacuum to yield pale yellow crude oil. The oil was washed with pentane (3 x 2 ml) to result in a white precipitate isolated in 65 %. Crystals suitable for x-ray diffraction were grown from a layered solution of C 6 D 5 Br / pentane solution at -40 ºC. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 4.98 (br s, 2H, NH 2 ), 3.17 (br q, 1H, 1 J B-H = 86 Hz, BH), 2.47 (m, 2H, N-Cy), 1.22 (m, 4H, Cy), 1.11 (m, 4H, Cy), 0.99 (m, 2H, Cy), (m, 10H, Cy); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F,, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 86 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 241 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (dm, 1 J C-F ~ 248 Hz, CF), (br, i- C 6 F 5 ), 55.8 (N-Cy), 29.3 (Cy), 23.8 (Cy), 23.7 (Cy). Elemental analysis calcd (%) for C 30 H 25 BF 15 N: C 51.82; H 3.62; N 2.01; Found: C 52.17, H 3.86; N Synthesis of [iprnh 2 (2-MeC 6 H 10 )][HB(C 6 F 5 ) 3 ] 5 In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-isopropyl-2-methylaniline (11.1 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a freezepump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 36 h. The solvent was removed under reduced vacuum and white precipitate was observed in the tube. The precipitate was washed with pentane (2 x 2 ml) and dried under vacuum to yield compound 5 in 77 %. Ratio of isomers A: B is 49 %. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 5.87 (br, 2H, NH 2 isomer A), 5.15 (br, 2H, NH 2 isomer B), 3.75 (br q, 2H, 1 J H-B = 82 Hz, BH), 3.18 (m, 1H, N-Cy isomer A), 3.13 (m, 2H, i Pr isomers A and B), 2.49 (m, 1H, N-Cy isomer B), (m, 18H, Cy isomers A and B), 1.13 (m, 9H, Me of i Pr isomer A, i Pr isomer B), 1.04 (d, 3H, 3 J H-H = 6 Hz, Me of i Pr isomer B), 0.86 (d, 3H, 3 J H-H = 6 Hz, Me isomer A), 0.77 (d, 3H, 3 J H-H = 6 Hz, Me isomer B); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 82 Hz, BH); 13 C { 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 235 Hz, CF), (dm, 1 J C-F ~ 246 Hz, CF), (dm, 1 J C-F ~ 249 Hz, CF), (br, i-c 6 F 5 ), 63.8 (N-Cy isomer B), 59.3 ( i Pr), 51.1 (N-Cy isomer A), 50.2 ( i Pr), 34.7 (Cy), 33.2 (Cy), 30.3 (Cy), 29.3 (Cy), 28.6 (Cy), 24.7 (Cy), 24.3 (Cy), 24.0 (Cy), 23.5 (Cy), 19.8 (Me of i Pr isomer A), 19.4 (Cy), 19.3 (Me of ipr isomer A), 18.6 ( i Pr isomer B), 17.5 (Me isomer A), 11.0 (Me isomer B). Synthesis of [iprnh 2 (4-MeC 6 H 10 )][HB(C 6 F 5 ) 3 ] 6 In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-isopropyl-4-methylaniline (11.1 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a freezepump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 36 h. The solvent was removed under reduced vacuum and white precipitate was observed in the tube. The precipitate was washed with pentane (2 x 2 ml) and dried under vacuum to yield compound 6 in 73 %. Ratio of isomers A: B is 80 %. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): 5.53 (br, 2H, NH 2 ), 3.71 (br q, 1H, 1 J H-B = 83 Hz, BH), 3.17 (m, 1H, 3 J H-H = 6 Hz, i Pr), 3.03 (m, 1H, N-Cy isomer A), 2.90 (m, 1H, N-Cy isomer B), 1.71 (m, 2H, Cy), 1.62 (m, 2H, Cy), 1.20 (m, 3H, Cy), 1.10 (d, 6H, 3 J H-H = 6Hz, i Pr), 0.86 (d,

4 3H, 3 J H-H = 7 Hz, Me), 0.77 ppm (m, 2H, Cy)]; 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 83 Hz, BH); 13 C { 1 H} NMR (100 MHz, C 6 D 5 Br, 298K) partial: δ (dm, 1 J C-F ~ 241 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (dm, 1 J C-F ~ 250 Hz, CF), 56.2 (N-Cy), 49.5 ( i Pr), 31.9 (Cy), 30.4 (CMeH), 29.1 (Cy), 21.0 (Me), 18.6 ( i Pr). Elemental analysis calcd (%) for C 28 H 23 BF 15 N: C 50.25; H 3.46; N 2.09; Found: C 50.14, H 3.48; N Synthesis of [iprnh 2 (4-MeOC 6 H 10 )][HB(C 6 F 5 ) 3 ] 7 In the glove box, a 50 ml Teflon screw cap glass bomb equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-isopropyl-4-methoxyaniline (12.2 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 36 h. The reaction tube was re-pressurized with H 2 after 1 day. The toluene was removed under reduced vacuum to yield a crude oil. The oil was washed with pentane (2 x 2 ml) and white precipitate compound 7 was isolated in 61 %. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 5.53 (br, 2H, NH 2 ), 3.71 (br q, 1H, 1 J H-B = 82 Hz, BH), 3.46 (br m, 4H, OMe and CHOMe), 2.99 (br m, 1H, N-Cy), 2.37 (m, 1H, i Pr), 1.62 (m, 2H, Cy), 1.29 (m, 2H, Cy), 1.07 (m, 4H, Cy), 0.81 (d, 6H, 3 J H-H = 6 Hz, ipr); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 82 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 235 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (br, i-c 6 F 5 ), 63.6 (OMe), 58.3 (CHOMe), 55.1 (N- Cy), 49.7 ( i Pr), 26.7 (Cy), 24.6 (Cy), 18.3 ( i Pr). Elemental analysis calcd (%) for C 28 H 23 BF 15 NO: C 49.08; H 3.38; N 2.04; Found: C 49.45, H 3.29; N Synthesis of [iprnh 2 (3-MeC 6 H 10 )][HB(C 6 F 5 ) 3 ] 8 In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-isoporpyl-3-methylaniline (11.1 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a freezepump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 36 h. The reaction tube was repressurized with H 2 after 1 day. The toluene was removed under reduced vacuum to yield a white precipitate. The product was washed with pentane (2 ml) and allowed to dry under vacuum. Compound 8 was isolated in 82 %. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 5.47 (br, 2H, NH 2 ), 3.69 (br q, 1H, 1 J H-B = 80 Hz, BH), 3.20 (m, 1H, i Pr), 2.97 (m, 1H, N-Cy), 1.71 (m, 3H, Cy), 1.53 (m, 1H, Cy), 1.12 (m, 1H, CMeH), 1.12 (d, 3H, 3 J H-H = 6 Hz, Me of i Pr), 1.11 (d, 3H, 3 J H-H = 6 Hz, Me of i Pr), 1.04 (m, 2H, Cy), 0.86 (d, 3H, 3 J H-H = 7 Hz, Me), 0.78 (m, 1H, Cy), 0.68 (m, 1H, Cy); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (d, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 80 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 237 Hz, CF), (dm, 1 J C-F ~ 250 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), 57.1 (N-Cy), 50.3 ( i Pr), 38.1 (Cy), 33.0 (Cy), 31.5 (CMeH),), 29.3 (Cy), 24.1 (Cy), 21.9 (Me), 19.6 (Me of i Pr), 19.2 (Me of i Pr). Elemental analysis calcd (%) for C 28 H 23 BF 15 N: C 50.25; H 3.46; N 2.09; Found: C 50.11, H 3.50; N 2.16.

5 Synthesis of [iprnh 2 (3,5-Me 2 C 6 H 9 )][HB(C 6 F 5 ) 3 ] 9 In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-isoporpyl-3,5-dimethylaniline (12.1 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 72 h. The reaction tube was re-pressurized with H 2 after 2 days. The toluene was removed under reduced vacuum to yield a crude oil. The oil was washed with pentane (3 x 2 ml) and compound 9 was isolated as a white precipitate in 48 %. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 5.55 (br, 2H, NH 2 ), 3.71 (br q, 1H, 1 J H-B = 82 Hz, BH), (br m, 2H, i Pr, N-Cy), 1.82 (br m, 1H, Cy), (m, 5H, Cy), 0.93 (m, 6H i Pr), (m, 1H, Cy), (m, 6H, Me), (m, 1H, Cy); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 82Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K) partial: δ (dm, 1 J C-F ~ 240 Hz, CF), (dm, 1 J C-F ~ 249 Hz, CF), (dm, 1 J C-F ~ 250 Hz, CF), (br, i-c 6 F 5 ), 56.0 (N-Cy isomer B), 52.7 (N-Cy isomer A), 49.4 ( i Pr), 49.3 ( i Pr), 41.0 (Cy), 37.8 (Cy), 37.7 (Cy), 36.6 (Cy), 33.8 (Cy), 30.1 (Cy), 27.0 (Cy), 24.9 (Cy), 21.2 (Me), 21.0 (Me), 18.8 ( i Pr), 18.6 ( i Pr), 18.3 ( i Pr), 17.3 (Me). Elemental analysis calcd (%) for C 29 H 25 BF 15 N: C 50.97; H 3.69; N 2.05; Found: C 50.87, H 3.99; N Synthesis of [CyNH 2 CHPhCH 2 Ph][HB(C 6 F 5 ) 3 ] 10 In the glove box, a 25 ml Teflon screw cap glass bomb equipped with a stir bar was charged with a solution of B(C 6 F 5 ) 3 (192 mg, 0.37 mmol) and cis-1,2,3-triphenylazirdine (101 mg, 0.37 mmol) in toluene (1 ml). The reaction tube was degassed three times through a freeze-pumpthaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. The reaction bomb was placed in a 110 ºC oil bath for 96 h. The reaction tube was re-pressurized with H 2 after 48 hrs. The toluene was removed under reduced pressure and the crude oil was washed with pentane (2 x 2 ml). The resulting powder was dissolved in minimum dichloromethane and placed in -40 ºC freezer for 24 hrs. Colourless crystals precipitated to yield compound 10 in 50 %. 1 H NMR (400 MHz, CD 2 Cl 2, 298K): δ 7.55 (m, 1H, p-ph), 7.45 (m, 4H, Ph), 7.40 (m, 3H, Ph), 7.20 (m, 2H, Ph), 5.88 (br, 2H, NH 2 ), 4.61 (t, 1H, 3 J H-H = 8 Hz, PhCH), 3.69 (br q, 1H, 1 J B-H = 85 Hz, BH), 3.44 (d, 2H, 3 J H-H = 8, PhCH 2 ), 3.06 (m, 1H, N-Cy), 2.03 (m, 1H, Cy), 1.68 (m, 4H, Cy), (br m, 5H, Cy); 19 F NMR (377 MHz, CD 2 Cl 2, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 21 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, CD 2 Cl 2, 298K): δ (d, 1 J B-H = 85 Hz, BH); 13 C NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 245 Hz, CF), (dm, 1 J C-F ~ 248 Hz, CF), (dm, 1 J C-F ~ 248 Hz, CF), (iph), (i-ph), (p-ph), (Ph), (Ph), (Ph), (p-ph), (Ph), (br, i-c 6 F 5 ), 64.1 (PhCH), 58.2 (N-Cy), 40.3 (PhCH 2 ), 30.6 (Cy), 28.9 (Cy), 24.1 (Cy), 23.8 (Cy), 23.6 (Cy). Elemental analysis calcd (%) for C 38 H 27 BF 15 N: C 57.52; H 3.43; N 1.77; Found: C 57.62, H 3.95; N Synthesis of [PhCH(CH 3 )NH 2 Cy][HB(C 6 F 5 ) 3 ] 11 In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (37.9 mg, mmol) and N-(1-phenylethylidene)aniline (14.4 mg, mmol) in toluene (2 ml). The reaction tube was degassed three times through a

6 freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 96 h. The toluene was removed under reduced vacuum to yield a crude oil. The oil was washed with pentane (3 x 2 ml) and white precipitate compound 11 was isolated in 57 %. 1 H NMR (C 6 D 5 Br): 7.35 (m, 3H, o,p- Ph), 7.21 (m, 2H, Ph), 6.18 (br, H, NH 2 ), 5.66 (br, 1H, NH 2 ), 4.28 (m, 1H, NH 2 CH), 3.83 (br q, 1H, 1 J H-B = 83 Hz, BH), 2.88 (m, 1H, N-Cy), 1.90 (m, 1H, Cy), 1.66 (m, 2H, Cy), 1.57 (m, 1H, Cy), 1.54 (d, 3H, 3 J H-H = 7 Hz, Me), 1.46 (m, 1H, Cy), 1.26 (m, 2H, Cy), 0.98 (m, 3H, Cy); 19 F NMR (377 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 20 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (d, 1 J B-H = 83 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 243 Hz, CF), (dm, 1 J C-F ~ 241 Hz, CF), (dm, 1 J C-F ~ 250 Hz, CF), (i-ph), (o-ph), (m-ph), 57.4 (NH 2 CH), 57.3 (N-Cy), 29.5 (Cy), 28.8 (Cy), 23.6 (Cy), 18.8 (Me). Elemental analysis calcd (%) for C 32 H 23 BF 15 N: C 53.58; H 3.23; N 1.95; Found: C 53.74, H 3.00; N Synthesis of [(iprnh) 2 C 6 H 10 ][HB(C 6 F 5 ) 3 ] 12 In the glove box, a 50 ml Teflon screw cap glass tube equipped with a stir bar was charged with a yellow solution of B(C 6 F 5 ) 3 (0.379 g, 0.74 mmol) in toluene (7 ml). To the tube, pale brown solid of N 1,N 4 -di(propan-2-ylidene)benzene-1,4-diamine ( g, 0.37 mmol) was added in its solid form(the diamine is slightly soluble in toluene). Instantaneously, the mixture became cloudy, viscous, and bright orange. The reaction tube was degassed three times through a freezepump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. After the addition of H 2 the reaction tube was placed in a 110 ºC oil bath for 72 h. The diamine completely dissolved at elevated temperatures to result in a clear yellow solution. The reaction tube was repressurized with H 2 after 1 day. White precipitate was observed in the yellow solution after 1 day. The toluene was removed under reduced pressure to yield a white precipitate and starting material. The crude precipitate was washed with pentane (4 x 2 ml) and allowed to dry under vacuum. Compound 12 was isolated in 64 %. This compound was slightly soluble in C 6 D 5 Br and CD 2 Cl 2. 1 H NMR (400 MHz, d 8 -THF, 298K): 7.84 (br, 2H, NH 2 ), 3.76 (br q, 1H, 1 J H-B = 92 Hz, BH), 3.64 (m, 1H, 3 J H-H = 6 Hz, i Pr), 3.35 (br m, 1H, N-Cy), 2.38 (d, 2H, 3 J H-H = 4 Hz, Cy), 1.59 (m, 2H, Cy), 1.38 (d, 6H, 3 J H-H = 6 Hz, i Pr); 19 F NMR (377 MHz, d 8 -THF, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 20 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, d 8 -THF, 298K): δ (d, 1 J B-H = 92 Hz, BH); 13 C{ 1 H} NMR (100 MHz, d 8 -THF, 298K): δ (dm, 1 J C-F ~ 237 Hz, CF), (dm, 1 J C-F ~ 242 Hz, CF), (dm, 1 J C-F ~ 246 Hz, CF), (br, i-c 6 F 5 ), 52.8 (N-Cy), 48.6 ( i Pr), 27.4 (Cy), 18.4 ( i Pr). Elemental analysis calcd (%) for C 48 H 30 B 2 F 30 N 2 : C 47.01; H 2.47; N 2.28; Found: C 46.86, H 2.47; N Synthesis of [ipr 2 NHPh][HB(C 6 F 5 ) 3 ] 13 In a glove box, B(C 6 F 5 ) 3 (37.9 mg, mmol) and N,N-diisopropylaniline (13.1 mg, mmol) were dissolved in C 6 D 5 Br (0.5 ml) and added into a Teflon cap sealed J-Young tube. The reaction tube was degassed three times through a freeze-pump-thaw cycle on the vacuum/h 2 line and filled with H 2 (4 atm) at -196 ºC. The tube was placed in a 110 ºC oil bath for 16 hrs. Pentane was added dropwise to the solution to give a white solid which was isolated in 87 % yield. Crystals suitable for x-ray diffraction were grown from a layered C 6 D 5 Br / pentane solution at -40 ºC. 1 H NMR (400 MHz, C 6 D 5 Br, 298K): δ 7.16 (m, 3H, o, p-c 6 H 5 ), 6.93 (m, 2H, m-c 6 H 5 ), 6.70 (br, 1H, NH), 3.71 (br q, 1H, 1 J H-B = 83 Hz, BH), 3.58 (m, 2H, 3 J H-H = 6 Hz, i Pr), 0.93 (d, 6H, 3 J H-H = 6 Hz, A Me of i Pr), 0.77 (d, 6H, 3 J H-H = 6 Hz, B Me of i Pr); 19 F NMR (377

7 MHz, C 6 D 5 Br, 298K): δ (m, 2F, o-c 6 F 5 ), (t, 1F, 3 J F-F = 20 Hz, p-c 6 F 5 ), (m, 2F, m-c 6 F 5 ); 11 B NMR (128 MHz, C 6 D 5 Br, 298K): δ (br d, 1 J B-H = 83 Hz, BH); 13 C{ 1 H} NMR (100 MHz, C 6 D 5 Br, 298K): δ (dm, 1 J C-F ~ 243 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (dm, 1 J C-F ~ 247 Hz, CF), (i-ph), (o-ph), (br, i-c 6 F 5 ), (m-ph), 58.4 ( i Pr), 18.8 ( A Me of i Pr), 16.8 ppm ( B Me of i Pr). Elemental analysis calcd (%) for C 30 H 21 BF 15 N: C 52.12; H 3.06; N 2.03; Found: C 51.83, H 3.29; N Theoretical Methods and Technical Details of the Computations The quantum chemical calculations have been performed with the TURBOMOLE suite of programs. [1] As Gaussian AO basis, triple-zeta (def-tzvp) sets of Ahlrichs et al. [2] have been employed for all atoms except for B, N and the added hydrogen molecule which are described by the larger def2-tzvpp basis in order to avoid BSSE effects. All geometries have been fully optimized at the DFT level using the TPSS density functional [3]. We included our standard atom pair-wise DFT-D3 (with BJ-damping) correction for intra-and inter-molecular dispersion (also called van der Waals) interactions [4]. The final level used for geometry optimization is dubbed TPSS-D3/def-TZVP' in the following. For a detailed description of the dispersion correction, that is of great importance in studies of large molecules, including many illustrative examples see Ref. [5], for the most recent chemical applications of this method see Ref. [6] In all DFT treatments, the RI-approximation has been used [7] for the Coulomb integrals which speeds the computations up significantly without any significant loss of accuracy. The numerical quadrature grid m4 (m5 for PWPB95, see below) has been employed for the integration of the exchange-correlation contribution. We report pure electronic energies without zero-point vibrational and thermal corrections as well as free enthalpies G(298) that are obtained by a standard rigid-rotor, harmonic vibrational statistical treatment. Vibrational frequencies are unscaled and values less than 50 wavenumbers are set to this value in order to prevent error in the entropy calculations. These calculations are also used to characterize the stationary points as minima or transition states (TS), respectively. For the dihydrogen activation TS we obtained an imaginary vibrational frequency of i852 cm -1. The corresponding normal mode represents the expected dissociation motion of H 2 and the CH bond formation, respectively. Single-point energy calculations for selected thermochemical properties were performed at the higher dispersion-corrected PWPB95 [9] double-hybrid functional level employing the def2-tzvpp basis set for all atoms. For the non-local perturbation part (all electrons correlated) in these calculations also the RI approximation using matching auxiliary basis functions [10] has been employed. This final theoretical level which should provide relative energies with an estimated accuracy of about 1-2 kcal/mol [9,11]. Covalent bond orders are calculated according to Wiberg [12] from the TPSS Kohn-Sham determinants. All energies and thermodynamic data for the investigated reactions are given below in tables S1 and S2. Solvent effects on the thermochemical properties have been estimated at the COSMO-RS level [13] (COSMOtherm software package [14] ) based on default BP86/TZVP calculations. Solvation contributions to free enthalpies at 298 K in toluene are computed and added to the gas phase values.

8 References [1.] Ahlrichs, R.; Bär, M.; Häser, M.; Horn, H.; Kölmel, C.; Chem. Phys. Lett. 1989, 162, 165. TURBOMOLE, version 5.9: Ahlrichs R. et al., Universität Karlsruhe See [2.] Weigend, F.; Ahlrichs, R.; Phys. Chem. Chem. Phys. 2005, 7, 3297.The basis sets are available from the TURBOMOLE homepage via the FTP Server Button (in the subdirectories basen, jbasen, and cbasen). See [3.] Staroverov, V. N.; Scuseria, G. E.; Tao, J.; Perdew, J. P.; J. Chem. Phys. 2003, 119, [4.] Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H.; J. Chem. Phys. 2010, 132, Grimme, S.; Ehrlich, S.; Goerigk, L.; J. Comput. Chem.., 2011, 32, [5.] Grimme, S.; Antony, J.; Schwabe, T.; Mück-Lichtenfeld, C.; Org. Biomol. Chem. 2007, 5, 741. Grimme, S.; WIRE Comput. Mol. Sci. 2011,1, [6.] Grimme, S.; Kruse, H.; Goerigk, L.; Erker, G.; Angew. Chem. Int. Ed. 2010, Schwabe, T.; Grimme, S.; Djukic, J.-P.; J. Am. Chem. Soc. 2009, 131, Kruse, H.; Grimme, S.; J. Phys. Chem. C 2009, 11, Mömming, M.; Frömel, S.; Kehr, G.;. Fröhlich, R; Grimme, S.; Erker, G.; J. Am. Chem. Soc. 2009, 131, S. Grimme, WIRE Comput. Mol. Sci., 2011, 1, 211. [7.] Eichkorn, K.; Treutler, O.; Öhm, H.; Häser, M.; Ahlrichs, R.; Chem. Phys. Lett. 1995, 240, 283. Eichkorn. K.; Weigend. F.; Treutler. O.; Ahlrichs. R.; Theor. Chem. Acc. 1997, 97, 119. [8.] Schäfer, A.; Horn, H.; Ahlrichs. R.; J. Chem. Phys. 1992, 97, [9.] Goerigk, L.; Grimme, S.; J. Chem. Theory Comput. 2011, 7, 291. [10.] Weigend, F.; Köhn, A.; Hättig, C.; J. Chem. Phys. 2002, 116, [11.] Goerigk, L.; Grimme, S.; Phys. Chem. Chem. Phys. 2011, 13, [12.] Wiberg, K. B.; Tetrahedron 1968, 24, [13.] Eckert, F.; Klamt, A. AlChE Journal 2002, 48, 369. [14.] Eckert, F.; Klamt, A.; COSMOtherm, Version C2.1, Release 01.11; COSMOlogic GmbH & Co. KG, Leverkusen, Germany, Computed reaction energies and contributions to thermodynamic properties Table S1: Computed a corrections (in kcal/mol) from energy to free enthalpy G(298) and solvation effects for the considered reactions. reaction Correction to H(298) Correction to G(298) Solvent correction to G(298) for toluene b FLP+H 2 vdw-complex

9 vdw-complex TS (barrier) VdW-complex CH intermediate FLP+H a TPSS-D3/def-TZVP' computed harmonic frequencies. Frequencies less than 50 cm -1 were set to this value to prevent errors in the entropy calculations. b COSMO-RS model. Table S2: Computed reaction energies and free enthalpies (in kcal/mol) at the two DFT levels. reaction TPSS-D3/def-TZVP' PWPB95-D3/def2-TZVPP E G(298) E G(298) G(298) in toluene FLP+H 2 vdwcomplex vdw-complex TS (barrier) vdw-complex CH intermediate FLP+H Optimized cartesian coordinates in Bohr and electronic energies in Hartree (TPSS- D3(BJ)/def-TZVP') H2, E= h h

10 FLP, E= n b c c c c c c c c c c c c c c c c c c c c c c

11 c c f f f f f f f f f f f f f f f c c c c h h h h

12 h h h h h h h h h h h vdw-complex, E= n b h h c c c c c c

13 c c c c c c c c c c c c c c c c c c c h h h h h h

14 f f f f f f f f f f f f f f f c c c h h h h h h h

15 h h CH-intermediate, E= b n h h c c c c c c c c c c c c c c c

16 c c c c c c c c c c h h h h h h f f f f f f f f f

17 f f f f f f c c c h h h h h h h h h 1 (H2 adduct), E= b n h

18 h c c c c c c c c c c c c c c c c c c c c c c c c

19 f f f f f f f f f f f f f f f h h h h h h c c c c

20 h h h h h h h h h TS, E= n b h h c c c c c c c c

21 c c c c c c c c c c c c c c c c h h h h h h f f f

22 f f f f f f f f f f f f c c c c h h h h h h h h h