Reaction of Tosylmethyl Isocyanide with Methyl 3-Substituted Propiolates as Acetylenic Michael Acceptors

Abstract

The reaction of tosylmethyl isocyanide (7) with methyl propiolate (14a), dimethyl acetylenedicarboxylate (14b), methyl 3-(2-furoyl) propiolate (14c), and methyl 3-benzoylpropiolate (14d) in the presence of an equimolar amount of base at room temperature gave the corresponding 1 : 2 adducts, i.e., methyl 3-(1-pyrrolyl) acrylate derivatives (16a, 16b, 16c, and 16d, respectively) as final products. The temperature dependence of the reaction made it possible to isolate the pyrroles (15a and 15b), postulated as intermediates of the reaction, at low temperature.