Transition Metal-Catalyzed Oxygenative α-Addition and β-Alkylation of Terminal Alkynes

Abstract

Described in this dissertation is the development of the transition metal-catalyzed cyclization and oxygenative nucleophilic addition of terminal alkynes which gives cyclopentane and cyclohexane carboxylic acid derivatives as products. Using terminal alkynes tethered with electrophiles such as alkyl halides, aldehydes, imines, and Michael acceptors, the reaction can be carried out with a broad range of nucleophiles such as alcohols and amines in the presence of a suitable base, oxidant and rhodium catalyst. The proposed mechanism involves the formation of a disubstituted metal vinylidene intermediate via β-alkylation followed by transfer oxygenation to form a metalloketene which then undergoes nucleophilic addition. This transformation can provide diverse ester and amide products while forming a 5- and 6-membered ring moiety.