Progress in nucleophilic catalysis and development of nickel-catalyzed cross-couplings of propargylic halides

Abstract

Chapter 1 describes the development of two organocatalytic processes. The first is a 13-alkylation reaction of Michael acceptors, and represents a novel umpolung process catalyzed by N-heterocyclic carbenes. The second section discusses the first successful phosphine-catalyzed, y-alkylation reaction of isomerizable allenoates. A highly enantioselective variant of this reaction is described. Chapter 2 discusses nickel-catalyzed cross-coupling reactions of secondary propargylic halides with a variety of organozinc nucleophiles. Section 2.2 describes progress toward an asymmetric alkylation reaction. In Section 2.3, the development of the first alkyl-alkyl secondary-secondary cross-coupling is described; Section 2.4 describes the application of this coupling reaction to the formal synthesis of a-cembra-2,7,1 1-triene-4,6-diol. The last section of this thesis (Section 2.5) discusses the development of the first asymmetric Negishi reaction of arylzinc reagents with secondary electrophiles.