Studies On Transiton-metal Catalyzed Cyclization Of Alkynes And C-H Functionalization

Carbon-Carbon bond and Carbon-Hetero bond coupling reactions are common but important in organic synthesis. More and more attentions are attracted to the construction of C-C and C-Het bonds by cyclization of alkynes and C-H functionalization using transition-metal (TM) as the catalysts. In this thesis, the reported research of Pd-catalyzed cyclization of alkynes and TM-catalyzed C-H activation is reviewed. Based on precious reports and our going research, we developed a new Pd-catalyzed cyclization of alkyne and copper catalyzed C-H functionalization. Results are summarized as follows:1) Pd-catalyzed synthesis of indeno furansA general and efficient synthesis of indeno[1,2]furans via a Pd-catalyzed bicyclization reaction between 2-alkynyliodobenzenes and propargylic alcohols is described. The procedure furnished indeno[1,2]furans with moderate to excellent yields and broad substrate scope. The cascade process combines the formation of one C-O bond and two C-C bonds in a single step.(Chapter 2)2) Copper catalyzed C-H cyanation of arenesAn efficient transformation from arenes to aryl cyanide using benzyl cyanide as the cyanide anion surrogate was developped. The reaction was conducted in the presence of CuBr, including copper-catalyzed aerobic oxidation of benzyl cyanide and copper-catalyzed C-H functionalization. Matching two Cu-catalyzed-reaction rates was the key for the successful transformation. (Chapter 3)3) Copper catalyzed C-H amidation of benzothiazolesAn efficient reaction of copper catalyzed C-H amidation between benzothiazols and aromatic acetonitriles was developped. In this reactioin, 2-(N-acylamino)benzothiazoles were efficiently obtained in one step under a mild condition. (Chapter 4)...