Regioselective hydrocarbonylation of phenylacetylene to α,β-unsaturated esters and thioesters with Fe(CO)5 and Mo(CO)6

A highly regioselective hydrocarbonylation of phenylacetylene with thiols and alcohols was developed using metal carbonyls/diazabicyclo[2.2.2]octane ( DABCO) system at 100 degrees C in DMF. The use of Mo(CO)(6) and thiols in the presence of DABCO was applied as an efficient Pd-free method for hydrothiocarbonylation of phenylacetylene into trans-alpha,beta-cinamyl thioesters in excellent yields ( 88-98%). Similar reaction using Fe(CO)(5)/ROH/DABCO system resulted into high yield synthesis of trans-alpha,beta-cinamyl esters ( 87-98%). These reactions were conducted under mild reaction conditions without the need to use gaseous CO or any phosphine ligand and palladium catalyst. (C) 2016 Published by Elsevier B.V.