Cross-coupling reactions in Cinchona alkaloid chemistry: aryl-substituted and dimeric quinine, quinidine, as well as quincorine and quincoridine derivatives
作者:Jens Frackenpohl、Wilfried M. Braje、H. Martin R. Hoffmann
DOI:10.1039/b004693k
日期:——
Cross-coupling reactions of modified Cinchona alkaloids provide access to a wide variety of novel arylated and dimeric derivatives of quinine and quinidine containing a single and double 1,2-amino alcohol functionality. Sonogashira and Heck reactions allow functionalization of ethynyl and 11-iodovinyl precursors. The role of bystander functionality is investigated.
palladium-catalyzed addition reactions of terminal alkynes (donors) to internal alkynes (acceptors). The enantiopure terminal alkynes were derivatives of quincoridine and quincorine, two semi-natural Cinchona alkaloids. The processes exhibited high chemoselectivity and excellent diastereoselectivity, the E-enynes being obtained as single products in almost all cases. The synthesis of new tetra and pentasubstituted