Premium
Fine Modification of Salen Ligands – Effects on the Salen–Ti‐Catalyzed Asymmetric Cyanosilylation of Aldehydes
Author(s) -
Lv Chengwei,
Cheng Qigan,
Xu Daqian,
Wang Shoufeng,
Xia Chungu,
Sun Wei
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201100319
Subject(s) - chemistry , trimethylsilyl cyanide , metal salen complexes , catalysis , enantiomer , enantiomeric excess , trimethylsilyl , enantioselective synthesis , organic chemistry , pyrrolidine , polymer chemistry , aldimine , diamine , medicinal chemistry
New bifunctional N ‐oxide salen–Ti IV complexes and a pyrrolidine salen–Ti IV complex in combination with achiral N ‐oxide were developed and applied to the asymmetric addition of trimethylsilyl cyanide to aldehydes. Notably, both enantiomers of trimethylsilyl ethers of cyanohydrins could be easily prepared by modifying the catalysts employed in this reaction, which are based on the same chiral diamine collar derived from L ‐tartaric acid. The products were obtained generally with moderate to good enantiomeric excesses and excellent yields by using relatively low catalyst loadings and only 1.05 equivalents of trimethylsilylcyanide (TMSCN).