I_(2)/Ph I(OAc)2-assisted oxidative C–H amination protocols toward metal-free pragmatic synthesis of pyrrolo2,3-bindoles

摘要

We report herein an I2/Ph I(OAc)2catalytic system for the pragmatic construction of C–N bonds through C–H/N–H oxidative coupling protocol.Divergent pyrrolo[2,3-b]indoles were efficiently prepared via I2-catalyzed intramolecular C–H amination reactions from(E/Z)-2-indolylenamines under metal-free conditions.Various functional groups are tolerated under mild reaction conditions and the resulting pyrrolo[2,3-b]indoles were obtained with mostly good to excellent yields.It was interesting to observe that both the(E)-and(Z)-isomers of the starting materials were efficiently transformed into the targeted product.The I+-mediated catalytic cycle was proposed based on mechanistic studies for this reaction.