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New Chiral Ligands with Nonstereogenic Chirotopic Centers for Asymmetric Synthesis
Author(s) -
Graf ClausDieter,
Malan Christophe,
Knochel Paul
Publication year - 1998
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/(sici)1521-3773(19981116)37:21<3014::aid-anie3014>3.0.co;2-6
Subject(s) - deprotonation , heteroatom , alkyl , chemistry , enantioselective synthesis , asymmetric carbon , carbon atom , stereochemistry , carbon fibers , center (category theory) , base (topology) , group (periodic table) , combinatorial chemistry , organic chemistry , crystallography , catalysis , materials science , mathematics , ion , composite material , composite number , mathematical analysis
Pseudo‐ C 2 ‐symmetrical ligands have been prepared efficiently: The attachment of the chiral alkyl group to the heteroatom (P or N) through a nonstereogenic, chirotopic carbon center facilitates their synthesis as the configuration at this carbon atom no longer needs to be controlled. Two such ligands were combined, for example, in the base 1 , which is especially useful for asymmetric deprotonation of prochiral ketones [Eq. (a)].