Highly Regioselective Fluorination and Iodination of Alkynyl Enolates
摘要:
A simple yet efficient approach to various functionalized quaternary alpha-alkynyl alpha-fluoro esters and gamma-iodoallenoates from readily available allenoates through an alkynyl enolate intermediate generated by LDA is presented. Reaction of this alkynyl enolate with NFSI gives the alpha-product (alpha-alkynyl-alpha-fluoro ester), whereas the reaction of the silyl ether of alkynyl enolate with I-2 gives solely the gamma-product (iodoallenoate).
Chiral Allenes via Alkynylogous Mukaiyama Aldol Reaction
作者:Aurélien Tap、Aurélie Blond、Vijay N. Wakchaure、Benjamin List
DOI:10.1002/anie.201603649
日期:2016.7.25
development of a catalyticenantioselective alkynylogous Mukaiyamaaldolreaction. The reaction is catalyzed by a newly designed chiral disulfonimide and delivers chiral allenoates in high yields and with excellent regio‐, diastereo‐, and enantioselectivity. Our process tolerates a broad range of aldehydes in combination with diverse alkynyl‐substituted ketene acetals. The reaction products can be readily