Intermediate as Catalyst: Catalytic Asymmetric Conjugate Addition of Nitroalkanes to α,β-Unsaturated Thioamides
作者:Takanori Ogawa、Shinsuke Mouri、Ryo Yazaki、Naoya Kumagai、Masakatsu Shibasaki
DOI:10.1021/ol202898e
日期:2012.1.6
Catalytic asymmetric conjugate addition of nitroalkanes to α,β-unsaturated thioamides is promoted by a mesitylcopper/(R)-DTBM-Segphos precatalyst, affording γ-nitrothioamides in moderate to high syn-selectivity and excellent enantioselectivity. The intermediate Cu-thioamide enolate functions as a soft Lewis acid/hard Brønsted base cooperative catalyst to drive the catalytic cycle efficiently under
催化不对称共轭加成到硝基烷烃α,β不饱和硫代酰胺由mesitylcopper促进/([R)-DTBM-SEGPHOS预催化剂,得到γ-nitrothioamides在中度至高度顺式-选择性和优良的对映选择性。中间的铜硫代酰胺醇烯酸酯充当软路易斯酸/硬布朗斯台德碱协作催化剂,以在质子转移条件下有效地驱动催化循环。