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Ti IV ‐Catalyzed Asymmetric Sulfenylation of 1,3‐Dicarbonyl Compounds
Author(s) -
Jereb Marjan,
Togni Antonio
Publication year - 2007
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.200700920
Subject(s) - catalysis , electrophile , enantioselective synthesis , steric effects , toluene , chemistry , chloride , medicinal chemistry , combinatorial chemistry , organic chemistry
The electrophilic enantioselective sulfenylation of 1,3‐dicarbonyl compounds with phenylsulfenyl chloride is effectively catalyzed by [Ti(TADDOLato)] complexes. The corresponding products are obtained in moderate to high yields. The highest ee values (up to 97 %) are obtained in toluene at room temperature and with a typical catalyst loading of 5 mol %. Bulky ester groups and sterically undemanding substituents at the α‐position were found to be crucial structural features of the starting materials in order to assure high enantioselectivity. The absolute configuration of one of the chiral products has been determined. The stereochemical course of the reaction is similar to that of analogous [Ti(TADDOLato)]‐catalyzed atom‐transfer reactions. A common side‐reaction the sulfenylated products undergo is a deacylation leading to racemic α‐sulfenylated esters.