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Palladium‐Catalyzed Desulfitative Mizoroki–Heck Couplings of Sulfonyl Chlorides with Mono‐ and Disubstituted Olefins: Rhodium‐Catalyzed Desulfitative Heck‐Type Reactions under Phosphine‐ and Base‐Free Conditions
Author(s) -
Dubbaka Srinivas Reddy,
Vogel Pierre
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200400838
Subject(s) - chemistry , rhodium , catalysis , sulfonyl , heck reaction , phosphine , medicinal chemistry , palladium , coupling reaction , base (topology) , organic chemistry , alkyl , mathematical analysis , mathematics
New conditions have been found for the desulfitative Mizoroki–Heck arylation and trifluoromethylation of mono‐ and disubustituted olefins with arenesulfonyl and trifluoromethanesulfonyl chlorides. Thus ( E )‐1,2‐disubstituted alkenes with high stereoselectivity and 1,1,2‐disubstituted alkenes with 12:1 to 21:1 E / Z steroselectivity can be obtained. Herrmann's palladacycle at 0.1 mol % is sufficient to catalyze these reactions, for which electron‐rich or electron‐poor sulfonyl chlorides and alkenes are suitable. If phosphine‐ and base‐free conditions are required, 1 mol % [RhCl(C 2 H 4 ) 2 ] catalyzes the desulfitative cross‐coupling reactions. Contrary to results reported for [RuCl 2 (PPh 3 ) 2 ]‐catalyzed coupling reactions with sulfonyl chlorides, the palladium and rhodium desulfitative Mizoroki–Heck coupling reactions are not inhibited by radical scavenging agents. Possible sulfones arising from the sulfonylation of alkenes at 60 °C are not desulfitated at higher temperatures in the presence of the Pd or Rh catalysts.