Isotopic labelling studies for a gold-catalysed skeletal rearrangement of alkynyl aziridines
作者:Paul W Davies、Nicolas Martin、Neil Spencer
DOI:10.3762/bjoc.7.96
日期:——
Isotopic labelling studies were performed to probe a proposed 1,2-aryl shift in the gold-catalysed cycloisomerisation of alkynyl aziridines into 2,4-disubstituted pyrroles. Two isotopomers of the expected skeletalrearrangement product were identified using (13)C-labelling and led to a revised mechanism featuring two distinct skeletalrearrangements. The mechanistic proposal has been rationalised against
进行同位素标记研究以探测在金催化的炔基氮丙啶环异构化成 2,4-二取代吡咯中所提出的 1,2-芳基位移。使用 (13) C 标记确定了预期骨骼重排产物的两种同位素,并导致了具有两种不同骨骼重排的修订机制。针对一系列 (13) C 和氘标记底物的反应,该机制建议已被合理化。
Asymmetric Sequential Corey–Chaykovsky Cyclopropanation/Cloke–Wilson Rearrangement for the Synthesis of 2,3-Dihydrofurans
作者:Yiming Zhou、Ning Li、Wei Cai、You Huang
DOI:10.1021/acs.orglett.1c03225
日期:2021.11.19
The first sequential Corey–Chaykovsky cyclopropanation/Cloke–Wilson rearrangement between propargyl sulfonium salts and acrylonitrile derivatives has been developed, affording the tetra-substituted 2,3-dihydrofurans in generally excellent yields (57–98%) with good diastereoselectivities (7:1–18:1). In addition, chiral propargyl sulfonium salt is also suitable for this strategy, giving the optically
One-Pot Synthesis of Cyclopropanes from Methylene Azabicyclo[3.1.0]hexanes Obtained by Formal Sequential [1+2]- and [2+3]-Cycloaddition Reaction of Prop-2-ynylsulfonium Salts and Tosylaminomethyl Enones
A formal sequential [1+2]‐ and [2+3]‐annulation of prop‐2‐ynylsulfonium salts and tosylaminomethyl enones was developed, constructing a series of methylene azabicyclo[3.1.0]hexanederivatives. A one‐pot procedure was established via hydration of an enamine intermediate to afford substituted cyclopropanes. Prop‐2‐ynylsulfonium salts acted as both C2 and C1 synthons in these two processes.
Counterion Effects in a Gold-Catalyzed Synthesis of Pyrroles from Alkynyl Aziridines
作者:Paul W. Davies、Nicolas Martin
DOI:10.1021/ol900609f
日期:2009.6.4
Aryl-substituted N-tosyl alkynyl aziridines undergo a gold-catalyzed ring expansion to afford 2,5-substituted pyrrole products. Under certain conditions, a ring-expansion and rearrangement leads to 2,4-substituted pyrroles. The reaction pathway is determined by the counterion to the gold catalyst.