The Ketene-Surrogate Coupling: Catalytic Conversion of Aryl Iodides into Aryl Ketenes through Ynol Ethers
作者:Wenhan Zhang、Joseph M. Ready
DOI:10.1002/anie.201405036
日期:2014.8.18
tert‐Butoxyacetylene is shown to undergo Sonogashira coupling with aryliodides to yield aryl‐substituted tert‐butyl ynol ethers. These intermediates participate in a [1,5]‐hydride shift, which results in the extrusion of isobutylene and the generation of aryl ketenes. The ketenes are trapped in situ with multiple nucleophiles or undergo electrocyclic ring closure to yield hydroxynaphthalenes and quinolines
Transition-Metal-Free Synthesis of Aryl-Substituted<i>tert</i>-Butyl Ynol Ethers through Addition/Elimination Substitution at an sp Centre
作者:Vincent J. Gray、Ben Slater、Jonathan D. Wilden
DOI:10.1002/chem.201203015
日期:2012.12.3
sulfonamide leads to displacement of the sulfonamide at the sp centre and isolation of the ynol ether in good yield in a single operation (see scheme). The mechanistic pathway has been probed by the use of coordinating additives, 13C‐labelling experiments and ab initio calculations, which indicated that an addition/elimination mechanism is in operation.