title: The benzylidenecarbene-phenylacetylene rearrangement: an experimental and computational study.
abstract: Benzylidenecarbene was generated from a new photochemical source, 1-benzylidene-1a,9b-dihydro-1H-cyclopropa[l]phenanthrene, in deuterated benzene at ambient temperature. The carbene undergoes a facile rearrangement to phenylacetylene and could not be trapped by olefins. Generation of the carbene bearing a (13)C label at the β-carbon produced phenylacetylene in which the label was found exclusively at the carbon adjacent to the phenyl ring. This overwhelming preference for H shift is consistent with B3LYP and CCSD(T) calculations. The label distribution observed in this work, however, contrasts previously reported high-temperature flash vacuum pyrolysis results where the interconversion of carbene and alkyne leads to the scrambling of labels over both alkynyl (sp) carbons.
authors.affiliation: Department of Chemistry, Colby College, Waterville, Maine 04901, United States.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Moore
authors.forename: Jesus S
authors.initials: JS
authors.lastname: Vidaurri-Martinez
authors.forename: Dasan M
authors.initials: DM
authors.lastname: Thamattoor
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry; D001597:Benzylidene Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D001597:Benzylidene Compounds; C581439:benzylidenecarbene; C044736:phenylacetylene; D000114:Acetylene