Stereo- and regioselective palladium-catalysed hydroarylation and hydrovinylation of functionalised alkynes: A route to substituted Z-2-cinnamyl esters, 3-chromen-2-ols, and coumarins

Article abstract of DOI:10.1055/s-1997-1040

The palladium-catalysed hydroarylation and hydrovinylation of methyl 3-phenylpropynoate and 3,3-diethoxy-1-(o-tetrahydropyranyloxy)phenyl-1-propyne with aryl and vinyl halides or inflates in the presence of Pd(OAc)₂ and KOOCH has been studied. The reaction affords stereoselectively syn addition products. The regiochemical outcome appears to be controlled by steric effects and the new carbon-carbon bond is generated preferentially on the carbon far from the aromatic ring ligated to the acetylenic carbon. The reaction can be applied to the synthesis of 3-substituted-3-chromen-2-ols and 3-substituted coumarins.