Palladium-Catalyzed Cycloalkylations of 2-Bromo-1,<i>n</i>-dienes with Organoboronic Acids
作者:Chang Ho Oh、Hye Rhyan Sung、Su Jin Park、Kyo Han Ahn
DOI:10.1021/jo025665t
日期:2002.10.1
Cascade palladium-catalyzed cycloalkylations of 2-bromo-1,n-dienes were accomplished in good to excellent yields, where the alkylpalladium intermediates, formed via an intramolecular Heck reaction of 2-bromo-1,n-dienes (n = 6 or 7), were successfully cross-coupled with various organoboronicacids. The optimal yields were achieved by the use of cesium carbonate in ethanol with Pd(PPh(3))(4) as catalyst
Suppressed β-Hydride Elimination in Palladium-Catalyzed Cascade Cyclization−Coupling Reactions: An Efficient Synthesis of 3-Arylmethylpyrrolidines
作者:Chi-Wan Lee、Kyung Seok Oh、Kwang S. Kim、Kyo Han Ahn
DOI:10.1021/ol0056426
日期:2000.5.1
A novel type of palladium-catalyzed cascade cyclization-coupling reaction that proceeds with suppressed beta-hydride elimination has been found. One of the N-sulfonyl oxygens is suggested to coordinatively stabilize an alkylpalladium intermediate, thus preventing the intermediate from the usual beta-elimination, This is the first sequential palladium-catalyzed coupling reaction where the Suzuki and Heck reactions can compete. The reaction provides an efficient synthetic route to 4-methylene-3-arylmethylpyrrolidines, which are not readily available by other routes.