Carboalumination Reactions

Abstract

AbstractThis chapter deals with the carboalumination of alkenes and alkynes including dienes, diynes, and enynes. The zirconium‐catalyzed methylalumination of alkynes (Negishi ZMA reaction), the zirconium‐catalyzed asymmetric carboalumination of alkenes (Negishi ZACA reaction), and the cyclic carboalumination reactions of alkynes and alkenes (Dzhemilev cyclocarboalumination reaction) are discussed in great detail. The ZMA and ZACA reactions are covered in the following aspects: discovery of the reactions, synthetic methodological developments, mechanistic investigations of the reactions, and their applications in the natural product syntheses. Method developments include improvements on prototypical reactions, further transformations of the carboalumination products, and synergetic coupling of ZMA and ZACA reactions with other synthetic methods, such as palladium‐catalyzed cross‐coupling reactions. Discussion of the cyclic carboalumination is focused on the preparation of aluminacyclopentenes, aluminacyclopentadienes, and aluminacyclopentanes and their further transformations including the preparation of heterocyclic compounds containing N, O, S, Se, P, and B and interesting carbocycles. Recent studies on mechanisms of zirconium‐catalyzed carboalumination with triethylaluminum are described, which reveal multi‐pathway mechanisms leading to either a direct addition of ethyl carbon–metal bond to carbon–carbon multiple bonds or a cyclic carboalumination of alkenes and alkynes. Other metal‐catalyzed or uncatalyzed carboalumination reactions are also covered as appropriate.