METAL - PROMOTED CYCLIZATION AND TRANSITION - METAL - PROMOTED CARBONYLATIVE CYCLIZATION REACTIONS (ACYLPALLADATION, CARBOMETALLATION)
Abstract
The palladium catalyzed carbonylative intramolecular acylpalladation reaction across olefins cleanly gives cyclopentenone, cyclohexenone, and quinone derivatives in a predictable manner. A mechanistic sequence consisting of oxidative addition, CO insertion, acylpalladation, CO insertion, and methanolysis accounts for the formation of the cyclopentenones and cyclohexenones while oxidative addition, CO insertion, acylpalladation, and dehydropalladation accounts for the formation of quinones. The generation of zirconocene in the presence of (omega)-vinyl-1-silyl-1-alkynes produces the corresponding zirconabicyclic derivatives which are carbonylated with CO to give (alpha)-silylcyclopentenones. The zirconium promoted carboalumination of 4-halo-1-(trimethylsilyl)-1-butyne cleanly yields 2-methyl-1-(trimethylsilyl)cyclobutene which is used as a key intermediate in the total synthesis of grandisol.
Degree
Ph.D.
Subject Area
Organic chemistry
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.