Using Pd–salen complex as an efficient catalyst for the copper- and solvent-free coupling of acyl chlorides with terminal alkynes under aerobic conditions

The palladium–salen complex palladium(II) N,N′-bis{[5-(triphenylphosphonium)-methyl]salicylidene}-1,2-ethanediamine chloride was found to be a highly active catalyst for the copper- and solvent-free coupling reaction of terminal alkynes with different acyl chlorides in the presence of triethylamine as base, giving excellent ynones under aerobic conditions.