A glyoxylic acid-2-pyrrolidinone adduct leads to N-acyliminium-ion induced intermolecular electrophilic aromatic substitution yielding nitrogen-substituted phenylglycine derivatives, whereas the benzylamide of glyoxylic acid-2-pyrrolidinone adduct undergoes intramolecular amidoalkylation to give an isoquinolone type compound. High stereospecifity and enantioselectivity was observed in intermolecular amidoalkylation of benzene using glyoxylic acid-S-pyroglutamic acid ester or amide adducts.