Reaction of isoprene and dimethyl acetylenedicarboxylate in the presence of cyclododeca-1,5,9-trienylnickel: formation of cyclotetradecatetraene derivatives and a novel rearrangement of an intermediate π-allyl-nickel complex under the influence of carbon monoxide

Abstract

The reaction of dimethyl acetylenedicarboxylate with 2,6,11-trimethyl-,αω-dodecatrienediyl nickel (2), prepared from the reaction of isoprene with cyclododecatrienylnickel, at both 0 and –78 °C yields the fourteen-membered cyclic derivative (4) with 85% selectivity; on addition of carbon monoxide at –78 °C a novel rearrangement of the intermediate π-allylnickel complexes is observed which leads, eventually, to cyclic products with different isoprenoid arrangements.