Dehydrative cyclizations via acid catalysis as a method for molecular diversity

Abstract

Development of new synthetic methodologies that allow for efficient access to desirable core structures is a consistently valuable area of research for synthetic chemistry. Good methodologies provide rapid access to systematically varying compounds with desirable properties, enabling functional testing and the discovery of new, useful compounds and materials. Three novel synthetic methodologies that make use of dehydrative cyclizations of carbinols via Lewis acid catalysis have been developed towards this end: (1) A calcium-catalyzed, dehydrative, ring-opening cyclization of cyclopropyl carbinols to form (hetero)aryl-fused cyclohexa-1,3-dienes; (2) A Bi(OTf)3-catalyzed synthesis of α-alkylidene-γ-butyrolactones from the ring-opening cyclization of cyclopropyl carbinols; (3) A calcium-catalyzed synthesis of cyclopenta[b]thiophenes and indenes via dehydrative Nazarov-type electrocyclizations of alkenyl (hetero)aryl carbinols. The mechanistic details of how each of these methods perform have also been investigated. Initial results and proposals for consequent projects, which span the breadth of target synthesis and new methodologies, have also been established.