UC Santa Barbara

Despite the tremendous advance in homogeneous gold catalysis in the past decade or so, the functionalization of unactivated C(sp3)-H bonds, a highly desirable and yet challenging streamlining synthetic strategy, has so far rarely been realized in this ‘gold rush’. My graduate work was focused on the development of new strategies of gold catalysis to access highly reactive gold intermediates and harness their reactivities in insertion into unactivated C(sp3)-H bonds. Three approaches are discussed in this dissertation: (1) via gold vinylidenes: fully functionalized gold vinylidenes generated from simple TMS-terminated alkynones facilely insert into unactivated alkyl groups to furnish versatile 2-bromocyclopentenones; (2) via ‘gold benzyne’: gold-catalyzed cycloisomerizations of enediynes provide access to hypothetical ‘gold benzyne’ species, which exhibit reactivities distinctively different from transition metal-free benzynes, including insertions into unactivated C(sp3)-H bonds and regiospecific nucleophilic additions; (3) via oxidatively generated gold carbene: gold carbenes generated upon the oxidation of alkynones are demonstrated for the first time to be capable of inserting into unactivated C(sp3)-H bonds to yield cylcopentanones and cyclobutanones.