Reactions of salicyl N-tosylimines or salicylaldehydes with diethyl acetylenedicarboxylate for the synthesis of highly functionalized chromenes

Reactions of diethyl acetylenedicarboxylate with salicyl N-tosylimines or salicylaldehydes proceeded smoothly in the presence of DABCO or dimethylphenylphosphine under mild conditions to give the corresponding chromenes in excellent yields.

Reactions of diethyl acetylenedicarboxylate with salicyl N-tosylimines or salicylaldehydes proceeded smoothly in the presence of DABCO or dimethylphenylphosphine under mild conditions to give the corresponding chromenes in excellent yields.