Anion-induced enantioselective cyclization catalyzed by cationic gold catalysts

In this thesis the first highly enantioselective functionalization of terminal alkynes using gold(I) catalysts incorporating optically active counteranions is described. Cationic gold(I) catalysis was used in a novel asymmetric synthesis of substituted pyrrolidines, 2,3-dihydro-1H-pyrroles, and tetrahydrofurans from 1,4-diynamides, 1,6- diynamides, and 1,4-diynols, respectively. The role of counteranions in these transformations was studied and their employment found to be crucial for high selectivities. Utilizing the newly-developed catalytic system allows an access to the products in near quantitative yields and in good to excellent enantiomeric excesses.