Cannizzaro asymmetric

Unlike the starting material, the product of this reduction contains an asymmetric carbon atom and it was found to be optically active. Since in the case of ketones a Cannizzaro reaction cannot take place, this mechanism for alcohol formation is out of the question. Consideration of the reduction of ketones thus clearly shows that an actual biohydrogenation is involved. 

Bianchi, M., Matteoli, U., Menchi, G., Frediani, P., Piacenti, F. Asymmetric synthesis by chiral ruthenium complexes. VIII. The asymmetric Cannizzaro reaction. J. Organomet. Chem. 1982, 240, 65-70. 

On an alternative pathway, internal Cannizzaro reactions afford mandelic acid-type compounds from phenylglyoxal derivatives [152-156]. Copper complexes [153, 154], chromium perchlorate [154], cobalt Schiff s bases [155] and yttrium chloride [156] have been applied as catalysts. An asymmetric version [Eq. (7)] has been developed using phenylglyoxal (14) as substrate and a combination of Cu(OTf)2 and (S,S)-Ph-box 16 as the chiral catalyst [154]. After 24 h at room temperature isopropyl man-delate (15) was obtained with an enantioselectivity of 28% ee. 

---