Abstract
Preparation of heterocyclic compounds by the assembly of carbon-carbon and carbon-heteroatom unsaturated bonds via group 4 metallacycles was described. The preparative methods are classified into four categories : 1) reaction of metallacycles formed by the coupling of acetylenes and/or olefins with hetero-electrophiles, 2) coupling of two carbon-carbon unsaturated bonds and one carbon-heteroatom unsaturated bond, 3) coupling of one carbon-carbon unsaturated bond and two carbon-heteroatom unsaturated bonds, and 4) intramolecular hetero-metallation of functionalized acetylenes and allenes.
