作者:Daniel S. Levine、T. Don Tilley、Richard A. Andersen
DOI:10.1021/acs.organomet.6b00394
日期:2017.1.9
Terminal group 3 methylidene complexes are generated by thermolysis of monoanionic PNP-supported scandium and yttrium dialkyl complexes. The reaction mechanism has been probed by deuterium-labeling experiments and DFT calculations. Abstraction of a y-hydrogen from one alkyl group by the other affords a metal-lacyclobutane that undergoes [2 + 2] cycloreversion, analogous to a key step in the olefin metathesis reaction, to generate a methylidene complex and isobutene. The resulting methylidene complex dimerizes in the case of scandium and decomposes to a mixture of products in the case of yttrium.