Abstract
B-3-Pinanyl-9-borabicyclo[3.3.1]nonane (3-pinanyl-9-BBN, prepared from (+)-α-pinene and 9-BBN) is an effective chemical reagent for the asymmetric reduction of 1-deuterio aldehydes to chiral 1-deuterio primary alcohols. For example, benzaldehyde-1-d is reduced to pure (S)-(+)-benzyl-1-d alcohol. A deuterated reagent prepared from α-pinene and 9-BBN-9-d was found to reduce a variety of aromatic, aliphatic, and α,β-unsaturated aldehydes to the corresponding chiral primary 1-deuterio alcohols. In each case a large excess of the R enantiomer is formed. Steric factors seem to have little effect on the extent of asymmetric induction, but electron-donating para substituents on benzaldehyde slightly decrease the enantioselectivity of the reduction. A number of other chiral-9-BBN derivatives were investigated. A model is proposed to account for the high asymmetric inductions.
Original language | English (US) |
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Pages (from-to) | 2352-2355 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 101 |
Issue number | 9 |
State | Published - 1979 |
ASJC Scopus subject areas
- Chemistry(all)