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Palladium‐Catalysed Direct Regioselective Synthesis of Cyclic Ketals from Electron‐Rich Olefins and Aryl Bromides in Ionic Liquids
Author(s) -
Hyder Zeynab,
Mo Jun,
Xiao Jianliang
Publication year - 2006
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200606151
Subject(s) - chemistry , aryl , ionic liquid , regioselectivity , palladium , halide , catalysis , organic chemistry , cationic polymerization , coupling reaction , solvent , combinatorial chemistry , heck reaction , alkyl
The Heck reaction comprises one of the most important carbon‐carbon coupling reactions in organic synthesis. The popularity of the reaction is attributable to the broad availability of aryl halides and to the tolerance of the reaction for a wide variety of functional groups. Reported herein is a direct method for the highly regioselective preparation of 5‐membered and 7‐membered cyclic ketals in respectable to good yields from aryl bromides ( 1a–k ) and electron‐rich olefins ( 2a and b ). The reaction is performed with palladium catalysis using ionic liquid as solvent with no need for any halide scavengers, providing an alternative to the use of aryl triflates. The ionic liquid is found to direct the reaction pathway towards exclusive α‐arylation via a cationic route.