INFLUENCE OF PI-BACK-BONDING ON THE REACTIVITY OF THE NITROSYL GROUP - NITROSATION OF ACTIVATED METHYLENE-COMPOUNDS VIA NITROSYL-RUTHENIUM COMPLEXES

In an effort to probe the mechanism of nitrosation of activated methylene compounds through nitrosyl complexes, the reactions of a series of β -diketones with neutral nitrosyl-ruthenium complexes Ru(AB)2NOX have been investigated (AB is the monoanion of 2,4,6-trioxo-5-oximinopyrimidine or l,3-dimethyl-2,4,6-trioxo-5-oximinopyrimidine; X = Cl, Br, OH, NO2). The rate of the nitrosation reaction is strongly dependent on the acidity of the activated methylenes, the nature of the solvent, and the coordination environment of the nitrosyl group. The latter behavior is assessed in terms of the nitrosylπ∗ acceptor orbital. © 1979, American Chemical Society. All rights reserved.