Intramolecular Cyclization of Radicals Generated from α-Halomethylsulfonamides
摘要:
A series of homologous alpha-sulfonamidyl radicals has been generated by reaction of alpha-halomethyl precursors with tri-n-butyltin hydride under AIBN catalysis. The intramolecular cyclization Capability of these highly reactive intermediates has been evaluated. Where possible, five-membered sultams are formed by 5-exo transition states. The longer C-SO2 and SO2-NR2 bonds have little demonstrable effect on this pathway. In larger systems, however, the 7-endo option predominates over the 6-exo alternative. A preparatively useful route to sultams has emerged from this investigation.