β-Nitrostyrenes as Electrophiles in Parham Cyclization Chemistry. Reaction with o-Lithiobenzonitrile

Abstract

β-Nitrostyrenes react with o-lithiobenzonitrile, generated from the requisite aryl bromide at −100 °C by bromine–lithium exchange with n-butyllithium in THF, to afford 2-nitro-3-phenyl-3H-inden-1-ylamines resulting from 1,4-addition to the β-nitrostyrene followed by intramolecular capture of the resultant nitronate anion by the ortho-cyano functional group.