| This thesis has two main parts. Part I is composed of two chapters which describe new and convenient method for allenylsilane synthesis and formal ene-type reaction of silylallenes with triplet oxygen. Part II consists of two chapters describing Au- and Ag-catalyzed cascade reactions involving cyclization and trapping of the resulting oxocarbenium intermediates with weak nucleophiles, and hydroarylation of arynes catalyzed by silver for biaryl synthesis Specifically, in chapter one, synthetic methods for allenes and reactions of allenylsilanes are briefly reviewed in introduction. Reaction scope for allenylsilane synthesis from ketones and its mechanism are discussed. In chapter two, a brief summary of ene reaction, especially singlet oxygen ene reaction, is presented. The generality for autooxidation of silylallenes and its mechanistic study are discussed. In chapter three, a brief survey for Au- and Ag-catalyzed cyclization reactions and trapping of oxocarbenium intermediate is provided.The reaction scope of cascade reaction involving Au- and Ag-catalyzed cyclization of alkynol and phosphonation and allylation of resulting oxocarbenium intermediate is discussed. Finally, in chapter four, methods for constructing biaryls were briefly reviewed and the reactivity of arynes toward arenes is provided in introduction. The development of inter- and intramolecular hydroarylation or arynes with a Ag catalyst and its reaction mechanism are discussed. |
