Table 1.
NHC-Cu-catalyzed ECA with various aryl(dimethyl)aluminum reagents.[a]
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| Entry | Ar1 | Ar | Product | Conv. [%];[b]
Yield [%][c] |
Ar vs. Me addn[b] |
e.r.[d] |
| 1 | 2-thienyl; 2c | Ph | 3b | 73; 57 | >98:2 | 92:8 |
| 2 | oFC6H4; 2d | Ph | 3c | 88; 33 | 55:45 | >99:1 |
| 3 | pF3CC6H4; 2e | Ph | 3d | 89; 76 | 92:8 | 94:6 |
| 4 | pMeOC6H4; 2f | Ph | 3e | >98; 82 | >98:2 | 98:2 |
| 5 | Ph; 2b | pF3CC6H4 | 3f | >98; 82 | 92:8 | 98:2 |
| 6 | Ph; 2b | pMeOC6H4 | 3g | >98; 77 | >98:2 | >99:1 |
| 7 | 3-thienyl; 2a | pF3CC6H4 | 3h | >98; 83 | >98:2 | 96:4 |
| 8 | 3-thienyl; 2a | pMeOC6H4 | 3i | >98; 89 | >98:2 | >99:1 |
[a]
Reactions were performed under N2 atmosphere.
[b]
Determined through analysis of 400 MHz 1H NMR spectra of unpurified mixtures.
[c]
Yield of isolated and purified products.
[d]
Determined by HPLC analysis (±2%); see the Supporting Information for details.