Asymmetric anti-Selective Michael Reaction of Imidazole-Modified Ketones with trans-β-Nitroalkenes

作者:Yang, Dongxu; Wang, Linqing; Li, Dan; Han, Fengxia; Zhao, Depeng; Wang, Rui*
来源:Chemistry - A European Journal, 2015, 21(4): 1458-1462.
DOI:10.1002/chem.201405847

摘要

The successful application of imidazole-modified ketones in asymmetric anti-selective Michael reactions with trans-beta-nitroalkenes is presented by employing a newly developed 3-bromothiophene-modified chiral diamine ligand. The corresponding conjugate adduct was submitted to further transformations with Grignard reagents to solve the problem of a-site selectivity of simple linear ketones. Additionally, the syn-selective product was obtained by treating the anti-selective adduct with a simple base. In this way, the site-specific products for both diastereomers in the asymmetric conjugate addition of simple ketones to nitroalkenes can be obtained.