Patent ID: 7504542

Claim:
In a method for the preparation of α-hydroxy ketones by acyloin addition of aldehydes, the improvement comprising catalyzing said addition using a catalyst of formula II or III: wherein: R 1 and R 2 are the same or different and are each a C 6 -C 10 -aryl, heteroaryl, branched or unbranched, optionally mono- or poly-C 1 -C 4 -alkyl- or -heteroalkyl-substituted C 1 -C 10 -alkyl, C 3 -C 6 -cycloalkyl or mono- or poly-C 1 -C 4 -alkyl-substituted C 6 -C 10 -aryl, and R 3 and R 4 are the same or different and are each hydrogen, branched or unbranched C 1 -C 6 -alkyl, C 3 -C 6 -cycloalkyl, C 6 -C 10 -aryl or heteroaryl.