Palladium Catalysed Tandem Cyclisation–Anion Capture Processes. Part 4: Organotin(IV) Transfer Agents
摘要:
Palladium(0) catalysed cascade mono- and bis-cyclisation-anion capture involving a wide variety of starter species, terminating species and organotin(IV) anion capture reagents are reported leading to a range of bridged, fused and spirocyclic products. The diastereoselectivity of the bis-cyclisation processes is explained in terms of steric effects in the transition states. (C) 2000 Elsevier Science Ltd. All rights reserved.
Palladium-Catalyzed Carbohalogenation: Bromide to Iodide Exchange and Domino Processes
作者:Stephen G. Newman、Jennifer K. Howell、Norman Nicolaus、Mark Lautens
DOI:10.1021/ja206099t
日期:2011.9.28
Aryl bromides have been used to prepare a variety of nitrogen- and oxygen-containing heterocycles featuring new carbon-carbon and carbon-iodine bonds. This palladium-catalyzed carbohalogenation requires potassium iodide for the reaction to proceed in high yields. Additionally, the first examples of domino carbohalogenation reactions have been demonstrated using both aryl iodide and aryl bromide starting materials. Complex products with multiple rings and stereogenic centers are generated in excellent yields with moderate to excellent diastereoselectivities.