19978-30-4Relevant academic research and scientific papers
Evidence for the existence of group 3 terminal methylidene complexes
Levine, Daniel S.,Tilley, T. Don,Andersen, Richard A.
supporting information, p. 80 - 88 (2017/11/27)
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 γ-hydrogen from one alkyl group by the other affords a metallacyclobutane 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.
Tertiary alcohols by tandem β-carbolithiation and N→C aryl migration in enol carbamates
Fournier, Anne M.,Clayden, Jonathan
, p. 142 - 145 (2012/02/14)
Enol carbamates (O-vinylcarbamates) derived from aromatic or α,β-unsaturated compounds and bearing an N-aryl substituent undergo carbolithiation by nucleophilic attack at the (nominally nucleophilic) β position of the enol double bond. The resulting carbamate-stabilized allylic, propargylic, or benzylic organolithium rearranges with N→C migration of the N-aryl substituent, creating a quaternary carbon α to O. The products may be readily hydrolyzed to yield multiply branched tertiary alcohols in a one-pot tandem reaction, effectively a polarity-reversed nucleophilic β-alkylation-electrophilic α-arylation of an enol equivalent.
