Diorganozinc reagents enantioselection addition

The enantioselective addition of organometallics to aldehydes is a useful approach to optically active secondary alcohols. Diorganozinc reagents add with excellent enantioselectivity to aldehydes in the presence of a chiral catalyst such as 1,2- or 1,3-amino alcohols (see equation 14 and Table 2). In most cases, diethylzinc has been used, but the reaction could be extended to some other dialkylzinc reagents and to divinylzinc. Alkylzinc halides afford secondary alcohols with a substantially lower enantiomeric excess. Many aldehydes are good substrates, "- but the best results are usually obtained with aromatic aldehydes. ... 

Table 2 Catalysts (50)-(65) for the Enantioselective Addition of Diorganozinc Reagents to Aldehydes ...

Further applications to the preparation of chiral polyoxygenated molecules ]302] and to the synthesis of the natural product (-)-mucocin [303] have been reported. The enantioselective addition of the functionalized diorganozinc reagent... 

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