Abstract
Starting from inexpensive enantiopure (R)- and (S)-mandelic acid, a range of α-hydroxy-2-oxazolines has been prepared. The synthesis
involves the condensation of the acid chloride with a vicinal amino alcohol, followed
by intramolecular cyclization to form the oxazoline ring. The resulting compounds
have been used as ligands in the asymmetric phenyl transfer reaction to 4-chlorobenzaldehyde,
employing a mixture of triphenylborane and diethylzinc as the phenyl source. Good
yields (up to 76%) and moderate enantioselectivities (up to 35%) have been achieved.
Key words
asymmetric catalysis - mandelic acid - organometallics - oxazolines - phenyl transfer
- zinc
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