A practical and highly efficient method for the construction of a variety of sulfonamides mediated by I2 was demonstrated. The reaction proceeds readily at room temperature using a variety of sodium sulfinates and amines or ammonia in water in a metal-, base-, ligand-, or additive-free protocol. Primary, secondary and tertiary sulfonamides were obtained in good to excellent yields with a broad range of substrate tolerability.

Enol ether structural motifs exist in many highly oxygenated biologically active natural products and pharmaceuticals. The synthesis of the geometrically less stable Z-enol ethers is challenging. An efficient Z-selective oxidative isomerization process of allyl ethers catalyzed by a cobalt­(II) (salen) complex using N-fluoro-2,4,6-trimethylpyridinium trifluoromethanesulfonate (Me3NFPY•OTf) as an oxidant has been developed. Thermodynamically less stable Z-enol ethers were prepared in excellent yields with high geometric control. This methodology also demonstrates the effectiveness in controlling the Z-selective isomerization reaction of diallyl ethers at room temperature. This catalytic system provides an alternative pathway to extend the traditional reductive isomerization of allyl ethers.

An original and efficient synthesis of 3,3-difluoro-2-oxindole derivatives has been developed via copper/Bpin-catalyzed difluoroacetylation of aniline via C-H activation followed by intramolecular amidation. In this method, amino groups in primary, secondary or tertiary anilines act as directing groups, providing ortho-difluoroacetylated products regioselectively. And in the first two cases, further intramolecular amidation affords 3,3-difluoro-2-oxindole derivatives via a one-pot strategy. This method facilitates the synthesis of compound A as a potent and selective EP receptor antagonist in only five steps in 13% yield instead of the previously reported nine steps in overall 4% yield.

A copper-catalyzed hydrofluoroacetylation of arylacetylenes or alkynyl carboxylic acids with bromofluoroacetates was developed. The reaction shows excellent stereoselectivity to afford fluoroacetylated alkenes in good to excellent yields with a broad substrate scope.