Introduction of terminal alkynes into the 2-and 8-positions of the Troger's base core via Sonogashira reaction of 2,8-diiodo-4,10-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine

Conditions for the introduction of terminal alkynes into the 2- and 8-positions of the Troger's base core via Sonogashira reaction of 2,8-diiodo-4,10-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine were established. Only the use of the bulky and electron-rich phosphine P(t-Bu)(3) as a ligand for the palladium catalyst allowed for the Sonogashira reaction to proceed effectively. In addition, excessive equivalents of the alkyne were found to increase the yields of the coupling. The established optimal conditions for the introduction of terminal alkynes into the Troger's base core were applied to differently aryl- and pyridyl-substituted terminal alkynes to afford new analogues of Troger's base 3a-g in moderate to excellent yields.