Enantioselective rhodium-catalyzed conjugate alkynylation of 5-benzylidene Meldrum's acids with TMS-acetylene.

The enantioselective alkynylation of benzylidene Meldrum's acids has been successfully achieved through rhodium-catalyzed addition of TMS-acetylene in the presence of bisphosphine ligand 3,5-Xylyl-MeOBIPHEP. The resulting Meldrum's acids were obtained in good yields and up to 99% enantiomeric excess. The alkynylation method is carried out under mild reactions conditions and is compatible with an array of functional groups.