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
Enantioselective Oxidative Cross-Coupling Reaction of 3-Indolylmethyl CH Bonds with 1,3-Dicarbonyls Using a Chiral Lewis Acid-Bonded Nucleophile to Control Stereochemistry
作者:Chang Guo、Jin Song、Shi-Wei Luo、Liu-Zhu Gong
DOI:10.1002/anie.201002108
日期:——
A highly enantioselective CH‐activation‐based oxidativecouplingreaction of 3‐arylmethylindole derivatives with dibenzyl malonate by using chiral Lewis acid bonded nucleophiles provided an approach to indole derivatives (see scheme; DDQ=2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone, OTf=trifluoromethanesulfonate).
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.
l rearrangement has been successfully developed. This methodology allows for efficient conversion of a wide range of indoles into the synthetically significant 2,2-disubstituted indolin-3-ones, the core structure of pseudoindoxyl alkaloids, under mild reaction conditions.