Synthesis of unsymmetrical 2,4-diaryl substituted and 3-bromo-2-(4-bromoalkoxy)-derived pyranocoumarins

Abstract

A series of unsymmetrical 2,4-disubstituted pyranocoumarins and 3-bromo-2-(4-bromoalkoxy)-derived pyranocoumarins were synthesized via the palladium-catalyzed C–H arylation of 4-phenyl-4H,5H-pyrano[3,2-c]chromen-5-ones with aryl iodide and the three-component reaction of 4-phenyl-4H,5H-pyrano[3,2-c]chromen-5-one with bromine and cyclic ether, respectively.