Table 1.
| |||||
---|---|---|---|---|---|
entry | R1 | R2 | mol %Er(OiPr)3 | % yield 7 (8)b | time (min) |
(silacycle) | |||||
1 | Me | H (6a) | 5 | 50 (32) | 5 |
2 | iPr | H (6b) | 5 | 50 (28) | 40 |
3 | Me | Me (6c) | 5 | 62 (3) | 60 |
4 | Me | Me (6c) | 10 | 84 (6) | 30 |
5 | Me | Me (6c) | 1 | trace | 120 |
Conditions: 1.5 equiv of PhCHO, 2.0 equiv of 6, [1]0 = 0.2 M.
Yields determined by 1H NMR versus an internal standard.