Thermal Ring Contraction of Dibenz[<i>b,f</i>]azepin-5-yl Radicals: New Routes to Pyrrolo[3,2,1-<i>jk</i>]carbazoles
作者:Lynne A. Crawford、Hamish McNab、Andrew R. Mount、Stuart I. Wharton
DOI:10.1021/jo800637u
日期:2008.9.1
Flash vacuum pyrolysis (FVP) of N-allyl- or N-benzyldibenz[b,f]azepine at temperatures from 750 to 950 degrees C gives pyrrolo[3,2,1-jk]carbazole as the major product. The mechanism of the ring contraction involves dibenzazepin-1-yl radical formation, followed by transannular attack and formation of a 2-(indol-1-yl)phenyl radical which cyclizes. The mechanism is supported by independent generation