Table 1.
Scope of the catalytic process and the effect of alkene:electrophile ratio.
| |||||
|---|---|---|---|---|---|
|
| |||||
| Entry | Ar; Electrophile | Alkene: Electrophile | Product | Conv. (%)*; Yield (%)† | e.e.§ |
| 1 | Ph; 1a | 3:1 | 2a | >98; 67 | 90 |
| 2 | o-MeOC6H4; 1a | 3:1 | 2b | >98; 55 | 90 |
| 3 | o-FC6H4; 1a | 3:1 | 2c | 98; 54 | 78 |
| 4 | o-F3CC6H4; 1a | 3:1 | 2d | >98; 46 | 66 |
| 5 | 2-naphthyl; 1a | 3:1 | 2e | >98; 65 | 78 |
| 6 | m-(pin)BC6H4; 1a | 3:1 | 2f | >98; 44 | 66 |
| 7 | m-tert-BuO2CC6H4; 1a | 3:1 | 2g | >98; 69 | 64 |
| 8 | p-MeOC6H4; 1a | 3:1 | 2h | >98; 28 | 94 |
| 9 | p-FC6H4; 1a | 3:1 | 2i | >98; 66 | 84 |
| 10 | p-(pin)BC6H4; 1a | 3:1 | 2j | >98; 48 | 64 |
| 11 | p-tert-BuO2CC6H4; 1a | 6:1 | 2k | 22; 14 | 2 |
| 12 | p-F3CC6H4; 1a | 3:1 | 2l | >98; 70 | 16 |
| 13 | 3-Boc-indolyl; 1a | 3:1 | 2m | >98; 58 | 96 |
|
| |||||
| 14 | 2-naphthyl; 1a | 1:3 | 2e | 80; 50 | 92 |
| 15 | m-(pin)BC6H4; 1a | 1:3 | 2f | 71; 52 | 93 |
| 16 | m-tert-BuO2CC6H4; 1a | 1:3 | 2g | 83; 62 | 90 |
| 17 | p-(pin)BC6H4; 1a | 1:3 | 2j | 66; 56 | 84 |
| 18 | p-tert-BuO2CC6H4; 1a | 1:3 | 2k | >98; 72 | 4 |
| 19 | p-F3CC6H4; 1a | 1:3 | 2l | >98; 79 | 34 |
|
| |||||
| 20 | Ph;
|
3:1 | 2n | >98; 60 | 80 |
| 21 | Ph;
|
1:3 | 2n | >98; 51 | 92 |
| 22 | Ph;
|
3:1 | 2o | 45; 29 | 80 |
| 23 | Ph;
|
1:6 | 2o | >98; 84 | 90 |
| 24 | Ph;
|
3:1 | 2p | >98; 63 | 90 |
| 25 | Ph;
|
1:3 | 2p | 88; 73 | 92 |
|
| |||||
| 26 |
o-FC6H4;
|
1:3 | 2c | 79; 64 | 92 |
| 27 |
o-F3CC6H4;
|
1:3 | 2d | 68; 50 | 92 |
| 28 |
p-FC6H4;
|
3:1 | 2i | >98; 65 | 96 |
| 29 |
p-F3CC6H4;
|
3:1 | 2l | >98; 68 | 92 |
Reactions were carried out under N2 atmosphere with L3a as the chiral ligand, except for L3b in the case of 2n, 2o and 2p).
*
Conv. determined by analysis of the 1H NMR spectra of the unpurified mixtures (±2%).
†
Yields are of isolated and purified product (±5%); differences between conv. and yield is due to allyl–B(pin) formation (excess alkene) or of proto-boryl addition products (excess allyl electrophile).
§
Enantiomeric excess (e.e.) determined by HPLC analysis (±1%). Experiments were performed at least in triplicate. See the Supplementary Information (Section 5) for experimental and analytical details. pin, pinacolato; Boc, tert-butoxycarbonyl.