anti-Carbozincation of Diethyl Acetylenedicarboxylate

Significance

In this work, a radical carbozincation of diethyl acetylenedicarboxylate is described. The reaction is performed in the presence of air at room temperature and leads exclusively to fumaric acid ester derivatives via an anti-selective coordination-controlled alkylzinc group radical transfer. This is complementary to well-known carbocupration protocols, which display the reverse selectivity at low temperature.