The Cu‐free asymmetric allylic alkylation, catalysed by NHC, with Grignardreagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignardreagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives
Enantioselective Synthesis of All-Carbon Quaternary Stereogenic Centers via Copper-Catalyzed Asymmetric Allylic Alkylation of (<i>Z</i>)-Allyl Bromides with Organolithium Reagents
作者:Martín Fañanás-Mastral、Romina Vitale、Manuel Pérez、Ben L. Feringa
DOI:10.1002/chem.201406006
日期:2015.3.9
A copper/phosphoramidite catalyzed asymmetric allylic alkylation of Z trisubstituted allyl bromides with organolithium reagents is reported. The reaction affords all‐carbon quaternary stereogenic centers in high yields and very good regio‐ and enantioselectivity. This systematic study illustrates the crucial role of the olefin geometry of the allyl substrate on the outcome of the reaction and provides