A facile and efficient synthesis of substituted indeno[2,1-c]quinolin-6(7H)-ones from a variety of α-acyl N-arylcinnamamides mediated by polyphosphoric acid (PPA) is described, and a mechanism involving the formation of a dicationic superelectrophile and subsequent double intramolecular nucleophilic cyclization reactions is proposed.

A highly regioselective synthesis of 3-arylamino- and 5-arylaminoisoxazoles from enaminones based on reaction condition selection is reported. 3-Arylaminoisoxazoles were produced by treating enaminones with aqueous hydroxylamine in DMF at 100 °C, whereas 5-arylaminoisoxazoles were synthesized by subjecting enaminones to aqueous hydroxylamine in the presence of KOH and TBAB in water under reflux. A mechanism for the regioselective synthesis of 3-arylamino- and 5-arylaminoisoxazoles is proposed.

A facile and efficient synthesis of substituted quinolin-2(1H)-ones is developed via intramolecular cyclization of penta-2,4-dienamides mediated by concentrated H2SO4 (98%), and a mechanism involving the formation of a dicationic superelectrophile, and subsequent intramolecular nucleophilic cyclization reactions is proposed.

A facile and efficient synthesis of substituted quinolin-2(1H)-ones is developed via intramolecular cyclization of penta-2,4-dienamides mediated by concentrated H2SO4 (98%), and a mechanism involving the formation of a dicationic superelectrophile, and subsequent intramolecular nucleophilic cyclization reactions is proposed.