ASYMMETRIC HYDROFORMYLATION OF UNSATURATED ESTERS WITH PtCl(SnCl3) CATALYST

Article abstract of DOI:10.1016/0022-328X(87)80296-6

Dimethyl 2-(formylmethyl)butanedioate (2e) has been synthesizes regioselectively with an enantiomeric excess of more than 82percent by the homogeneous catalytic hydroformylation of dimethyl itaconate (1e) with PtCl(SnCl3)<(R,R)-DIOP> as the catalyst precursor.Under the conditions used a competitive hydrogenation to dimethyl 2-methylsuccinate (3e) takes place.This reaction occurs with an optical yield of up to 51percent.For other vinylidene esters 1 the asymmetric induction was lower both in the hydroformylation and in the competitive hydrogenation.The relationship between the absolute configuration of the predominant antipodes and the possible transition states responsible for the enantioface discrimination is discussed in terms of a model developed and successfully used for olefinic hydrocarbons as substrates.