Preparation and heterocyclization reactions of ferrocenylazido ketones.: Useful building blocks for the synthesis of ferrocenyl-substituted azaheterocycles

Several kinds of ferrocenylaryl ketones bearing an azido functionality at the ortho-position of the aryl ring have been prepared and they have proven to be useful building blocks for the synthesis of azaheterocycles. Thus, thermally induced azide decomposition of these compounds allows the formation of ferrocene-substituted 2,1-benzisoxazoles and indoles. Moreover, the Staudinger reaction with triphenylphosphine followed by aza-Wittig reaction of the resulting iminophosphorane with isocyanates provides access to ferrocene-substituted quinolines and quinazolinones. (C) 1999 Elsevier Science S.A. All rights reserved.