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Novel binuclear chiral zirconium catalysts used in enantioselective strecker reactions
Author(s) -
Kobayashi Shū,
Ishitani Haruro
Publication year - 2000
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/(sici)1520-636x(2000)12:5/6<540::aid-chir42>3.0.co;2-p
Subject(s) - strecker amino acid synthesis , chemistry , enantioselective synthesis , catalysis , nitrile , imine , zirconium , aldehyde , organic chemistry , amine gas treating , medicinal chemistry
A novel binuclear chiral zirconium catalyst was successfully used in enantioselective Strecker reactions. The catalyst was readily prepared from zirconium t ‐butoxide (Zr(O t Bu)4), ( R )‐6,6′‐dibromo‐1,1′‐bi‐2‐naphthol (( R )‐6‐Br‐BINOL), and ( R )‐3,3′‐dibromo‐1,1′‐bi‐2‐naphthol (( R )‐3‐Br‐BINOL) to form unique binuclear structure. It was revealed that a combination of ( R )‐6‐Br‐BINOL and ( R )‐3‐Br‐BINOL was essential in these asymmetric reactions and that much lower selectivities were obtained by using other combinations. Two‐component (an imine and hydrogen cyanide (HCN)) and three‐component (an aldehyde, an amine, and HCN) Strecker reactions proceeded smoothly in the presence of a catalytic amount of the chiral zirconium catalyst to afford the corresponding α‐amino nitrile derivatives in high yields with high enantioselectivities. Chirality 12:540–543, 2000. © 2000 Wiley‐Liss, Inc.