Facile synthesis of HFIP esters-containing 2H-benzopyrans through palladium-catalyzed one-pot cyclization/carbonylation using formic acid as the CO source

An efficient and straightforward procedure for the synthesis of HFIP esters-containing 2H-benzopyrans has been established through palladium-catalyzed one-pot cyclization/carbonylation reaction of substituted propargyl ethers with HFIP by using formic acid as the CO precursor. A diverse set of 2H-benzopyrans have been formed with HFIP esters as attractive functional groups in moderate to excellent yields. This protocol features broad substrate scopes and no manipulation of toxic CO gas.