I. Yavari et al., REACTION BETWEEN TERT-BUTYL ISOCYANIDE AND DIMETHYL ACETYLENEDICARBOXYLATE IN THE PRESENCE OF CH-ACIDS, Journal of chemical research. Synopses, (10), 1994, pp. 384-385
The highly reactive 1:1 intermediate produced in the reaction between
tert-butyl isocyanide and dimethyl acetylene-dicarboxylate is trapped
by CH-acids to yield enamines.