Highly (E)-Selective BF3·Et2O-Promoted Allylboration of Chiral Nonracemic α-Substituted Allylboronates and Analysis of the Origin of Stereocontrol
摘要:
delta-Methyl-substituted homoallylic alcohols 2 were prepared in 71-88% yield, E:Z>30:1 and 93% to >95% ee via BF3 center dot Et2O-promoted allylboration with alpha-Me-allylboronate 1. The origin of high (E)-selectivity is proposed.
Highly (E)-Selective BF3·Et2O-Promoted Allylboration of Chiral Nonracemic α-Substituted Allylboronates and Analysis of the Origin of Stereocontrol
摘要:
delta-Methyl-substituted homoallylic alcohols 2 were prepared in 71-88% yield, E:Z>30:1 and 93% to >95% ee via BF3 center dot Et2O-promoted allylboration with alpha-Me-allylboronate 1. The origin of high (E)-selectivity is proposed.
Application of Vinyl Nucleophiles in Matteson Homologations
作者:Thorsten Kinsinger、Uli Kazmaier
DOI:10.1021/acs.orglett.2c01119
日期:2022.5.27
nucleophiles was found to be a versatile tool for the synthesis of highly substituted and functionalized allyl boronic esters. High yields and stereoselectivities are obtained with sterically demanding alkyl boronic esters and/or Grignard reagents. With the application of such vinyl Matteson homologations, the polyketide fragment of lagunamide B is synthesized.
发现与乙烯基亲核试剂的 Matteson 同系化是合成高度取代和功能化的烯丙基硼酸酯的通用工具。使用空间要求高的烷基硼酸酯和/或格氏试剂可获得高产率和立体选择性。通过应用这种乙烯基 Matteson 同系物,合成了 lagunamide B 的聚酮化合物片段。