Method for the asymmetric hydrogenation of olefins utilising photoisomerisation
申请人:DSM IP Assets B.V.
公开号:EP2213638A1
公开(公告)日:2010-08-04
The present invention relates to a method for the preparation of a compound of formula (I),
wherein R1 is different to R2; R3 is different to R4; and R1, R2, R3 and R4 are each a moiety other than hydrogen, which method comprises,
i) photoirradiating at an intensity above ambient intensity a solution comprising a compound of formula (II),
wherein R1, R2, R3 and R4 are as defined above, to form a solution of a mixture of compounds of formula (IIa) and (IIb),
wherein R1, R2, R3and R4 are as defined above; and
ii) contacting the mixture of compounds (IIa) and (IIb) with a hydrogen donating agent in the presence of an asymmetric hydrogenation catalyst, after initiation of i) and before termination of i).