Preparation of Highly‐Substituted Pyridines via Diels‐Alder Reactions of Vinylallenes and Tosyl Cyanide

Abstract

Abstract This chapter presents the procedure for preparation of highly‐substituted pyridines via Diels‐Alder reactions of vinylallenes and tosyl cyanid. The procedures in Organic Syntheses are intended for use only by persons with proper training in experimental organic chemistry. All hazardous materials should be handled using the standard procedures for work with chemicals described in references such as “Prudent Practices in the Laboratory”. The development of practical and efficient methods for the construction of highly substituted pyridines remains a challenging goal for organic synthesis. Vinylallenes are reactive dienes in Diels‐Alder reactions which engage in cycloadditions with triple bonds to afford isoaromatic products that isomerize to aromatic systems spontaneously or under mild conditions. The authors have developed several strategies for the synthesis of highly substituted pyridines based on the cycloadditions of vinylallenes with nitrogen heterodienophiles. The chapter also describes the optimal conditions for the Diels‐Alder reaction of vinylallene 2 and tosyl cyanide.