Azomethinylides generated by reaction of difluorocarbene with N-alkyl- and N-arylimines of O-acylated salycilaldehyde undergo intramolecular 1,3-dipolar cycloaddition to the ester carbonyl group forming regioselectively 2,5-epoxy-1,4-benzoxazepine derivatives.
Copper-catalyzed oxidative esterification of ortho-formyl phenols without affecting labile formyl group
作者:Yong Zheng、Wei-Bin Song、Li-Jiang Xuan
DOI:10.1016/j.tetlet.2015.06.024
日期:2015.7
A copper-catalyzed oxidativeesterification of ortho-formyl phenols with aldehydesusing TBHP as oxidant in water is developed. Besides aromatic and aliphatic aldehydes, benzylic alcohols are also suitable for this reaction. The sensitive formyl group remains intact under oxidative conditions. This method provides an alternative protocol for classical esterification reactions.
Azomethine ylides derived from dichlorocarbene and O-acylsalicylaldehyde anils in the synthesis of 2,5-epoxy-2,3,4,5-tetrahydro-1,4-benzoxazepin-2-ones and 2-aminoethanols
作者:I. V. Voznyi、M. S. Novikov、A. F. Khlebnikov、R. R. Kostikov
DOI:10.1023/b:rucb.0000041304.68814.83
日期:2004.5
Iminiodichloromethanides generated by the reaction of O-acylsalicylaldehyde anils with dichlorocarbene undergo regioselective intramolecular 1,3-dipolar cycloaddition to the ester carbonyl group to give 2,5-epoxy-2,3,4,5-tetrahydro-1,4-benzoxazepin-2-ones. These compounds are expedient precursors for the synthesis of N-(2-hydroxybenzyl)ethanolamines.