C2-symmetric proline-derived tetraamine as highly effective catalyst for direct asymmetric Michael addition of ketones to chalcones
作者:Shijun Ma、Lulu Wu、Ming Liu、Yongmei Wang
DOI:10.1039/c2ob06897d
日期:——
A C2-symmetric tetraamine catalyst was developed for the asymmetricMichaeladdition of ketones to chalcones. The corresponding adducts 1,5-dicarbonyl compounds were obtained in good chemical yields with high levels of diastereo- and enantioselectivities (up to >99 : 1 dr and 93% ee) under mild conditions. By studying the ESI-MS of the intermediates, a proposed mechanism was disclosed.
Pyrrolidine–pyridine base catalysts for the enantioselective Michael addition of ketones to chalcones
作者:Da-Zhen Xu、Sen Shi、Yingjun Liu、Yongmei Wang
DOI:10.1016/j.tet.2009.09.001
日期:2009.11
A series of pyrrolidine-pyridine base organocatalysts have been developed and 3a found to be a highly effective catalyst for the asymmetric Michael addition reactions of ketones to chalcones. The reaction generated the corresponding products 1, 5-diketones in excellent diastereoselectivities (up to >99:1 dr) and enantioselectivities (up to 100% ee). (c) 2009 Elsevier Ltd. All rights reserved.