Preparation of α-Imino Aldehydes by [1,3]-Rearrangements of O-Alkenyl Oximes
摘要:
The synthesis of alpha-imino aldehydes has been achieved through the thermal [1,3]-rearrangement of O-alkenyl benzophenone oximes. A copper. mediated C-O bond coupling between benzophenone oxime and alkenyl boronic acids provides facile access to the required O-alkenyl oximes and a Horner-Wadsworth-Emmons olefination can be applied to the a-imino aldehyde products to give gamma-imino-alpha,beta-unsaturated esters. The scope of the method is described and mechanistic experiments are discussed.
Stereospecific Synthesis of Vinyl(phenyl)iodonium Tetrafluoroborates via Boron-Iodane Exchange of Vinylboronic Acids and Esters with Hypervalent Phenyliodanes
Reaction of vinylboronic acids and esters with hypervalent phenyliodanes in the presence of BF3-Et2O undergoes boron-iodane exchange at O degrees C in dichloromethane yielding vinyl(phenyl)iodonium tetrafluoroborates stereoselectively with retention of configuration. (C) 1997 Elsevier Science Ltd.