Effective Modular Iminooxazoline (IMOX) Ligands for Asymmetric Catalysis: [Zn(IMOX)]-Promoted Enantioselective Reduction of Ketones by Catecholborane

Angewandte Chemie - International Edition

Volumn 42, Issue 40, 2003, Pages 4928-4930

  Locatelli, Manuela ^a   Cozzi, Pier Giorgio ^a  

^a UNIVERSITY OF BOLOGNA   (Italy)

Author keywords

Alcohols; Asymmetric catalysis; Enantioselectivity; Ligand design; Reduction

Indexed keywords

KETONES; REDUCTION; ZINC COMPOUNDS;

NUCLEOPHILIC ATTACK;

CATALYSIS;

ACETONE; CATECHOL DERIVATIVE; CATECHOLBORANE; IMINOOXAZOLINE; KETONE DERIVATIVE; OXAZOLINE DERIVATIVE; UNCLASSIFIED DRUG; ZINC COMPLEX;

ARTICLE; CATALYSIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; CHIRALITY; ENANTIOSELECTIVITY; REDUCTION; SYNTHESIS;

EID: 0242386504     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200351754     Document Type: Article

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44. The following aromatic ketones were reduced under the optimized reaction conditions: phenyl isopropyl ketone (60% yield, 49% ee), isovalerophenone (82% yield, 78% ee), α-bromoacetophenone (76% yield, 76% ee), and butyrophenone (84% yield, 85% ee).
45. To stress the importance of the hindered trityl group next to the imino moiety, IMOX ligands prepared from different aromatic and aliphatic amines were studied in the enantioselective reduction of acetophenone under the optimized reaction conditions. However, only racemic products or low enantiomeric excesses were obtained (see Supporting Information).