Enantioselective Alkoxycyclization of 1,6-Enynes with Gold(I)-Cavitands: Total Synthesis of Mafaicheenamine C

Identifier:  imarina:9172962

Handle: https://hdl.handle.net/20.500.11797/imarina9172962

Authors:  Martín-Torres, I; Ogalla, G; Yang, JM; Rinaldi, A; Echavarren, AM

Abstract:
Chiral gold(I)-cavitand complexes have been developed for the enantioselective alkoxycyclization of 1,6-enynes. This enantioselective cyclization has been applied for the first total synthesis of carbazole alkaloid (+)-mafaicheenamine C and its enantiomer, establishing its configuration as R. The cavity effect was also evaluated in the cycloisomerization of dienynes. A combination of experiments and theoretical studies demonstrates that the cavity of the gold(I) complexes forces the enynes to adopt constrained conformations, which results in the high observed regio- and stereoselectivities.