Regioselective synthesis of pyrrole and indole-fused isocoumarins catalysed by N $$^\wedge $$ ∧ O chelate ruthenium(II) complex

Abstract

Heterocyclic compounds containing pyrrole and indole-fused isocoumarins were obtained from a one-pot synthesis via annulations of N-heterocyclic carboxylic acids and alkynes with N ∧ O chelate ruthenium(II) complex, [RuCl(PySO 3)(p-cymene)] (PySO 3 = 2-pyridinesulfonate) in the presence of Cu(OAc) 2 H 2 O. The reaction proceeds efficiently in DMF but can also be performed in other solvents such as dichloroethane, t AmOH, and water. The annulations reaction is regioselective when performed 1-methylpyrrole-2-carboxylic acid with 1-phenyl-1-propyne.