Synthesis of areneacetylenic chelate complexes of chromium with a terminal triple bond, their reversible rearrangements to areneallenic chelates, and addition at the triple bond

New areneacetylenedicarbonylchromium chelate complexes containing the terminal acetylene fragment in the side chain of the arene ligand were synthesized. The rearrangement of these chelates to the previously unknown areneallenedicarbonylchromium chelate complexes was found and studied. It was demonstrated that this rearrangement is in principle reversible. For areneallenedicarbonylchromium chelates, a new example of metallotropic rearrangement was found and both isomers, namely, with the coordination either at the substituted or at the nonsubstituted double bond of the allene ligand, were detected for the first time. The coupled addition of the proton and the nucleophile at the coordinated triple bond afforded the corresponding areneolefin chelates. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1168–1175, June, 1999.