Complex BH3-ethylenediamin

Keywords ketone, enantioselective reduction, BH3-ethylenediamin complex, inclusion complex, alcohol... 

When a mixture of powdered ketone and NaBH4 is kept at room temperature, reduction of the ketone occurs to give the corresponding alcohol [2], When the reaction is carried out in inclusion crystals containing a chiral host compound, the optically active alcohol can be obtained by enantio-control of the reaction by the chiral host. For example, treatment of inclusion crystals of acetophenone (2a) or o-methylacetophenone (2b) and (S,S)-(-)-1,6-bis(o-chlorophenyl)-1,6-diphenylhexa-2,4-diyne-l,6-diol (1) [3] with powdered BH3-ethylenediamine complex (3) in the solid state gave 4a of 44 % ee (96 % yield) or 4b of 59 % ee (57 % yield), respectively [4],... 

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