143267-11-2Relevant academic research and scientific papers
Reactivity of functionalized arylcarbenes. 2-Phenylethyl side chains and hetero analogues
Kirmse, Wolfgang,Konrad, Wolfgang,Oezkir, Ismail S.
, p. 9935 - 9964 (2007/10/03)
Phenylcarbenes with -X-CH2Ph and -CH2-X-Ph (X = CH2, O, SiMe2) groups in the ortho position were generated thermally and photolytically from diazo or tosylhydrazone precursors. Stereorandom insertion reactions with β-C-H bonds were observed, pointing to a triplet abstraction-recombination mechanism. Large kinetic and stereochemical deuterium isotope effects support this notion. The ample formation of benzocyclobutenes from 2-CH2-X-Ph substrates is due to insertion of the carbenes into ArCH2-X bonds. Addition to the terminal phenyl groups competes with C-H and C-X insertion. The results of benzophenone sensitization and of trapping with methanol suggest that the intramolecular reactions of functionalized arylcarbenes proceed, at best, competitively with spin inversion.
