Asymmetric amplification in catalysis by trans-1,2-diaminocyclohexane bistriflamide.
A strong asymmetric amplification is observed in the addition of diethylzinc on aromatic aldehydes in the presence of the bistriflamide of trans-1,2-diaminocyclohexane 3a. The asymmetric amplification originates from the insolubility of the catalyst precursor 3a of low enantiomeric excess (ee), with a concomitant large increase of ee for the minor soluble part of 3a. Controlled mono-N-acetylation of 3a (20% ee) at -78 degrees C allowed isolation of 4 possessing 90% ee. [reaction: see text].
Satyanarayana
Tummanapalli
T
Laboratoire de Catalyse Moléculaire (UMR 8182), Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, 91405 Orsay, France.
Ferber
Benoit
B
Kagan
Henri B
HB
D000438:Alcohols / Q000138:chemical synthesis / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D003514:Cyclohexylamines / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D000438:Alcohols; D000447:Aldehydes; D003514:Cyclohexylamines; D009942:Organometallic Compounds; C030435:1,2-cyclohexanediamine; C454811:diethylzinc