Enantioselective Synthesis of Tertiary and Quaternary Stereogenic Centers: Copper/Phosphoramidite-Catalyzed Allylic Alkylation with Organolithium Reagents
作者:Martín Fañanás-Mastral、Manuel Pérez、Pieter H. Bos、Alena Rudolph、Syuzanna R. Harutyunyan、Ben L. Feringa
DOI:10.1002/anie.201107840
日期:2012.2.20
An efficient and highly enantioselectivecopper‐catalyzed allylic alkylation of disubstituted allyl halides with primary and secondary organolithium reagents using phosphoramidite ligands is reported. The use of trisubstituted allyl bromides allows, for the first time, the enantioselective synthesis of all‐carbon quaternary stereogenic centers with these reactive organometallic reagents.
Copper(<scp>i</scp>)-catalysed asymmetric allylic reductions with hydrosilanes
作者:T. N. Thanh Nguyen、Niklas O. Thiel、Johannes F. Teichert
DOI:10.1039/c7cc07008j
日期:——
copper(I)-catalysed asymmetric allylic reduction enables a regio- and stereoselective transfer of a hydride nucleophile in an SN2′-fashion onto allylic bromides. This transformation represents a conceptually orthogonal approach to allylic substitution reactions with carbon nucleophiles. A copper(I) complex based upon a chiral N-heterocyclic carbene (NHC) ligand allows for stereoselectivity reaching 99% ee
铜(I)催化的不对称烯丙基还原可实现S N 2'形式的氢化物亲核试剂的区域和立体选择性转移到烯丙基溴上。这种转变代表了与碳亲核试剂进行烯丙基取代反应的概念上正交的方法。基于手性N-杂环卡宾(NHC)配体的铜(I)配合物可使立体选择性达到99%ee。不管起始材料的双键构型如何,该催化剂都能进行立体收敛反应。
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