据报道,铑催化的1,1—二取代的烯丙基加氢甲酰化反应。使用Rh I / 6‐DPPon催化剂体系,可以以高区域选择性和化学选择性获得β,γ-不饱和醛。当不对称的1,1-二取代的丙二烯进入反应条件时,Z构型的产物具有高达> 95%的选择性。这是这些有趣的结构单元首次通过烯丙基的加氢甲酰化获得。通过对所获得的产物之一进行进一步的转化,证明了该方法的实用性。
Isomerizations of Propargyl 3-Acylpropiolates via Reactive Allenes
作者:Yuanxian Wang、Thomas R. Hoye
DOI:10.1021/acs.orglett.8b01705
日期:2018.8.3
Thermal isomerizations of various propargyl 3-acylpropiolates are described. Many result in the formation of 3-acylbutenolides. These reactions appear to proceed through intermediate 2,3-dehydropyrans (strained cyclic allenes), which then isomerize in a previously unobserved fashion. Competitive processes that provide additional mechanistic insights are also described.
Nickel(0)-Promoted Carboxylation of Allenamides with Carbon Dioxide via a Nickelalactone Intermediate
作者:Nozomi Saito、Yoshihiro Sato、Yasuyuki Sugimura
DOI:10.1055/s-0033-1340628
日期:——
Nickel(0)-promoted carboxylation of N-allenylamides (allenamides) with carbon dioxide proceeded via a nickelalactone intermediate to give beta-amino acid derivatives. It was also found that the regioselectivity at the oxidative addition stage was strongly affected by the substituents on the allene part.