Synthesis of α-vinylphosphonates from terminal alkynes and H-phosphonates as only the Markovnikov-regioisomer under metal- and solvent-free conditions.

An efficient triflic anhydride promoted phosphorylation of ketone was disclosed, and vinylphosphorus compounds were prepared under solvent-and metal-free conditions. Both aryl and alkyl ketones could perform smoothly to give vinyl phosphonates in high to excellent yields. In addition, the reaction was easy to carry out and easy to scale up. Mechanistic studies suggested that this transformation might involve nucleophilic vinylic substitution or a nucleophilic addition−elimination mechanism.

Fused furans are most commonly found units in natural products and medicinal molecules, and methods for their introduction are of fundamental importance. Here we report one-pot cycloadditions of ethynyl indoloxazolidones...