Domino‐ Heck Reactions of Carba‐ and Oxabicyclic, Unsaturated Dicarboximides: Synthesis of Aryl‐Substituted, Bridged Perhydroisoindole Derivatives

The CC coupling of the two bicyclic, unsaturated dicarboximides 5 and 6 with aryl and heteroaryl halides gave, under reductive Heck conditions, the C ‐aryl‐ N ‐phenyl‐substituted oxabicyclic imides 7a – c and 8a – c ( Scheme 3 ). Domino‐ Heck CC coupling reactions of 5, 6 , and 1b with aryl or heteroaryl iodides and phenyl‐ or (trimethylsilyl)acetylene also proved feasible giving 8, 9 , and 10a – c , respectively ( Scheme 4 ). Reduction of 1b with LiAlH 4 (→ 11 ) followed by Heck arylation and reduction of 5 with NaBH 4 (→ 13 ) followed by Heck arylation open a new access to the bridged perhydroisoindole derivatives 12a , b and 14a , b with prospective pharmaceutical activity ( Schemes 5 and 6 ).