Yoshihiro Matsumura

Catalytic activation of trichlorosilane for efficient and stereoselective reduction of ketones

Abstract Some kinds of N-formyl cyclic amine derivatives were found to be effective activators for trichlorosilane to reduce ketones. Namely, a catalytic amount of these activators were sufficient to complete the reduction of ketones with trichlorosilane, and the reduction of ketones by trichlorosilane with optically active activators gave enantiomerically enriched sec-alcohols in some extent of optical yields (up to 51% ee).

A new convenient method for selective monobenzoylation of diols

Abstract A new facile method for monoacylation of diols has been developed. A variety of cyclic and acyclic diols, in particular 1,2-diols, was selectively monobenzoylated in good yields by their reaction with benzoyl chloride in the presence of a catalytic amount of dimethyltin dichloride and inorganic bases.

The electrochemically induced Hofmann rearrangement and its comparison with the classic Hofmann rearrangement

The conditions suitable for the electrochemically induced (E-I) Hofmann rearrangement were scrutinized, and the E-I Hofmann rearrangement was compared with the classic Hofmann rearrangement. The E-I Hofmann rearrangement usually afforded reliable results with respect to the yields of the desired carbamates and the side products. Furthermore, by utilizing the advantage of the E-I Hofmann rearrangement which could be carried out in new solvent systems containing a variety of alcohols under mild conditions (neutral), a variety of carbamates possessing various functional groups were prepared.

New reaction conditions using trifluoroethanol for the E-I Hofmann rearrangement

The Hofmann rearrangement of N2-protected glutamine esters to N2-protected (2S)-4-[(2,2,2-trifluoroethoxy)carbonylamino]-2-aminobutyric acid esters was successfully achieved by an electrochemical method using a trifluoroethanol (TFE)–MeCN solvent system where the TFE may play an important role in controlling the basicity caused by electrochemically generated bases.