Asymmetric Allylation of Aldehydes Using a Chiral Cr(III) Complex

Significance

Under mild Lewis acidic conditions, a wide variety of aldehydes were converted into the corresponding enantioenriched homoallylic alcohols using simple alkyl halides and a chromium complex. Yields and enantioselectivities are generally high for allylation, with good anti:syn ratios for crotylation in addition to high enantioselectivities for each diastereomer. The reaction tolerates a range of aromatic substitutents, although neither substrates with strongly electron-withdrawing nor Lewis basic substitutents were reported.