Unexpected Migration and O to S Benzylic Shift of Thiocarbamate-containing Salicylaldehyde Derivatives.

Abstract

An unexpected reactivity of the O-dimethylthiocarbamate function has been evidenced concomitantly with the reduction of an aldehyde function presents at its ortho (o-) position. A systematic study using various substrates showed the exclusive formation of the rearranged compounds after 24 h and confirmed that the only-reduced compounds are reaction intermediates. However, electronic/steric contributions of the aromatic ring substituents on the composition of the reaction mixture (reduction of the aldehyde vs. migration) were observed at the early stage of the reaction (2 h). These new benzyl S-thiocarbamates compounds could be of particular interest as precursors for not trivial and functionalized free methylthiobenzyl alcohols.