Table 1.
Development of optimal conditions.
| |||||||
|---|---|---|---|---|---|---|---|
| entry | Cu salt (mol %) | ligand (mol %) | silane (equiv) | solvent | T (°C) | yield 3a, %a | yield aniline, %a |
| 1b | Cu(OAc)2 (10) | DPPB (20) | PhSiH3 (3) | PhMe | 100 | 42 | 54 |
| 2b | CuCl (10) | DPPB (20) | PhSiH3 (3) | PhMe | 100 | 25 | 0 |
| 3 | Cu(OAc)2 (10) | DPPB (20) | PhSiH3 (3) | PhMe | 100 | 65 | 32 |
| 4 | Cu(OAc)2 (10) | DPPB (20) | PhSiH3 (3) | 1,4-dioxane | 100 | 56 | 40 |
| 5 | Cu(OAc)2 (10) | DPPB (20) | PhSiH3 (3) | DCE | 100 | 52 | 42 |
| 6 | Cu(OAc)2 (10) | DPPB (20) | PhSiH3 (3) | MeCN | 100 | 52 | 28 |
| 7 | Cu(OAc)2 (5) | DPPB (10) | PhSiH3 (3) | MeCN | 100 | 55 | 26 |
| 8 | Cu(OAc)2 (2) | DPPB (4) | PhSiH3 (3) | MeCN | 100 | 50 | 31 |
| 9 | CuCl2 (5) | DPPB (10) | PhSiH3 (3) | MeCN | 100 | 35 | 50 |
| 10 | Cu(tfacac)2 (5) | DPPB (10) | PhSiH3 (3) | MeCN | 100 | 45 | 28 |
| 11 | CuSO4 (5) | DPPB (10) | PhSiH3 (3) | MeCN | 100 | 36 | 34 |
| 12 | Cu(OAc)2 (5) | DPPB (10) | PhSiH3 (3) | MeCN | 60 | 63 | 33 |
| 13 | Cu(OAc)2 (5) | DPPB (10) | PhSiH3 (3) | MeCN/PhMe (1:1) | 60 | 76 | 18 |
| 14 | Cu(OAc)2 (5) | DPPB (10) | iPr3SiH (4) | MeCN/PhMe (1:1) | 60 | 0 | 0 |
| 15 | Cu(OAc)2 (5) | DPPB (10) | (MeO)2MeSiH (3) | MeCN/PhMe (1:1) | 60 | 27 | 48 |
| 16 | Cu(OAc)2 (5) | DPPP (10) | PhSiH3 (3) | MeCN/PhMe (1:1) | 60 | 55 | 27 |
| 17 | Cu(OAc)2 (5) | BINAP (10) | PhSiH3 (3) | MeCN/PhMe (1:1) | 60 | 33 | 37 |
| 18 | Cu(OAc)2 (5) | 1,1-phen (10) | PhSiH3 (3) | MeCN/PhMe (1:1) | 60 | 0 | 90 |
| 19 | Cu(OAc)2 (5) | DPPB (10) | PhSiH3 (2.8) | MeCN/PhMe (1:1) | 60 | 83 | 16 |
| 20 | Cu(OAc)2 (5) | DPPB (10) | PhSiH3 (2.6) | MeCN/PhMe (1:1) | 60 | 80 | 20 |
a
As determined using 1H NMR spectroscopy using CH2Br2 as the internal standard.
b
1.5 equiv of ArNO2 and 1.0 equiv of ArB(OH)2 used.