Amides as precursors of imidoyl radicals in cyclisation reactions
作者:W. Russell Bowman、Anthony J. Fletcher、Jan M. Pedersen、Peter J. Lovell、Mark R.J. Elsegood、Elena Hernández López、Vickie McKee、Graeme B.S. Potts
DOI:10.1016/j.tet.2006.10.030
日期:2007.1
Amides have been successfully used as precursors of imidoyl radicals for radical cyclisation. The amides have been converted to imidoyl selanides via reaction with phosgene to yield imidoyl chlorides followed by reaction with potassium phenylselanide. Imidoyl selanides were reacted with tributyltin hydride (Bu3SnH) as the radical mediator with triethylborane or AIBN as initiators to yield imidoyl radicals
Imidoyl radicals, generated from imidoyl phenylselanide precursors, have been used for the synthesis of 2,3-disubstitutedindoles. A facile high yielding synthesis of imidoyl phenylselanides has been developed. The potential for neophyl rearrangement of 5-exo radical intermediates to 6-endo radical intermediates is discussed.