Iridium-catalyzed direct asymmetric vinylogous allylic alkylation
作者:Chang-Yun Shi、Jun-Zhao Xiao、Liang Yin
DOI:10.1039/c8cc07249c
日期:——
alkylation of α,β-unsaturated lactones (including coumarins) was achieved with excellent regio- and enantioselectivity. Transformations of the product were carried out by means of the versatile terminal olefin and lactonemoieties. The synthetic application of the present methodology was showcased by the asymmetric synthesis of an advanced synthetic Merck intermediate toward a new drug candidate.
An asymmetric vinylogous Mannich reaction between 3‐cyano‐4‐methylcoumarins and N‐Boc isatinimines catalysed by amide phosphonium salt is described. This method allows the formation of intriguing adducts bearing both 3‐aminooxindole and coumarin moieties in excellent yields with excellent enantioselectivities. The utility of this method was illustrated by a gram scale synthesis using as low as 0.1 mol %
the development of straightforward and efficient methodologies for the synthesis of readily functionalized chiral coumarins is of significant interest. Herein we report an enantioselectivecopper-catalyzed yne-allylic substitution of coumarins, resulting in a highly regioselective synthesis of diverse new classes of chiral coumarin derivatives with high efficiency and excellent functional group tolerance