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Catalytic and Highly Enantioselective Reactions of α‐Sulfonyl Carbanions with Chiral Bis(oxazoline)s
Author(s) -
Nakamura Shuichi,
Hirata Norimune,
Yamada Ryusuke,
Kita Takeshi,
Shibata Norio,
Toru Takeshi
Publication year - 2008
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.200800221
Subject(s) - enantioselective synthesis , oxazoline , carbanion , sulfonyl , chemistry , catalysis , enantiomer , enantiomeric excess , trifluoromethyl , stoichiometry , organic chemistry , sulfone , alkyl
Abstract The enantioselective reactions of lithiated benzyl trifluoromethyl sulfones with a substoichiometric amount of a bis(oxazoline) and various aldehydes is disclosed. The products were formed with excellent diastereo‐ and enantioselectivities. Fluorination of the sulfone with N ‐fluorobenzenesulfonimide and a stoichiometric amount of a bis(oxazoline) gave products with extremely high enantioselectivities (up to 99 % ee ; ee =enantiomeric excess). The enantioselective reaction was confirmed to proceed through a dynamic thermodynamic resolution pathway.