Oxidative alkynylation of acrylate esters with propargylic alcohols giving conjugated enyne esters was realized by use of a diene–rhodium catalyst. Propargylic alcohols were found to be useful alkynylating reagents in the present reaction to produce alkynylrhodium species via carbon–carbon bond cleavage. An excess of the acrylate ester worked as a hydride acceptor to reproduce the active rhodium species
The practical use of 2,2-dimethyl-2H-pyrans as electron-rich dienes in sequential Diels–Alder/retro-Diels–Alder (DA/rDA) domino processes to generate aromatic platforms has been demonstrated. Different polysubstituted alkyl 2-naphthoates have been synthesized by the DA/rDA reaction of benzynes and 2,2-dimethyl-2H-pyrans. The use of other activated alkynes allows the access of substituted alkyl benzoate