Enantioselective Rhodium-Catalyzed Conjugate Alkynylation of 5-Benzylidene Meldrum's Acids with TMS-acetylene

The enantiosetective 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.