Convergent Catalytic Asymmetric Synthesis of Esters of Chiral Dialkyl Carbinols
作者:Ze-Peng Yang、Gregory C. Fu
DOI:10.1021/jacs.0c01324
日期:2020.3.25
Because chiral dialkyl carbinols, as well as their derived esters, are significant as intermediates and end points in fields such as organic, pharmaceutical, and biological chemistry, the development of efficient approaches to their asymmetric synthesis is an important endeavor. In this report, we describe a method for the direct catalytic enantioselective synthesis of such esters, beginning with an
The cross-couplingreaction of allyl boronester with 1°/2°/3°-halogenated alkanes in the presence of copper has been developed for the first time, which provides a mild and efficient method for the construction of saturated C(sp3)–C(sp3) bonds. This protocol shows excellent compatibility with the nonactivated primary, secondary, and even tertiary halogenated alkanes under mild conditions.
An efficient method for the direct allylation of alkylhalides catalyzed by simple cobalt(II) bromide has been developed. This reaction, using a variety of substituted allylicacetates or carbonates, provides the linear product as the major product. It displays broad substrate scope and good functional group tolerance.
primary allyl chlorides with enantiocontrol at a useful level. The reaction generates a stereogenic quaternary carbon center having three sp3‐alkylgroups and a vinyl group. This protocol allowed the use of terminal alkenes as nucleophile precursors, thus representing a formal reductive allylic cross‐coupling of terminal alkenes. A reaction pathway involving addition/elimination of a neutral alkylcopper(I)
原位生成的手性Cu I / DTBM-MeO-BIPHEP催化剂系统与EtOK的结合使烷基硼烷试剂与γ,γ-二取代的伯烯丙基氯之间的对映选择性S N 2'型烯丙基交叉偶联以及对映体控制有效等级。该反应产生具有三个sp 3-烷基和一个乙烯基的立体异构的季碳中心。该协议允许使用末端烯烃作为亲核试剂的前体,因此代表了末端烯烃的正式还原性烯丙基交叉偶联。提出了一种涉及用烯丙基氯底物添加/消除中性烷基铜(I)物质的反应途径。
Copper-catalyzed Conjugate Additions of Alkylboranes to Aryl α,β-Unsaturated Ketones
Conjugate addition of alkylboron compounds (alkyl-9-BBN) to aryl α,β-unsaturated ketones proceeded in the presence of a catalytic amount (10 mol %) of [(IPr)CuCl] and t-BuOK. The alkylboranes are available through alkene hydroboration, and thus the overall process represents a reductive conjugate addition of alkenes to enone derivatives. A variety of functional groups are tolerated in both the alkenes and the α,β-unsaturated ketones.