Asymmetric cycloisomerization of 1,6-and 1,7-enynes by transition-metal catalysts

Highly functionalized carbo- and heterocycles can be prepared enantioselectively from simple enynes in transition-metal-catalyzed reactions. This versatile, atom-economic, and environmentally friendly approach has become a mainstay in natural product synthesis. The concise synthesis of (+)-pilocarpine is one example (see scheme). binap = 2,2′-bis- (diphenylphosphanyl)-1,1′-binaphthyl), cod = cyclooctacliene, RT = room temperature.