The gold-catalyzed 1,3-O-transposition reaction of ynesulfonamides provides a practical synthetic protocol for the synthesis of ynamides under mild conditions. This is the first 1,3-O-transposition example of ynesulfonamides in which a heteroatom is attached to the alkynyl terminal. A plausible mechanism is been proposed on the basis of ¹⁸O-labeling and control experiments as well as DFT calculation. By simple treatment, the obtained ynamides can easily be transformed into useful products.

Under mild reaction conditions, the C=C double bond inisatin-derived electron-deficient alkenes has been exclusively reduced in the presence of alkylphosphanes and water to afford the corresponding reduction products in good to excellent yields. A plausible mechanism is proposed on the basis of deuterium-labeling experiments.

The phosphane-catalyzed umpolung addition of various nucleophiles to ethyl 2-methyl-2,3-butadienoate is described. Oxygen, nitrogen, and carbon nucleophiles smoothly reacted with ethyl 2-methyl-2,3-butadienoate to give the corresponding umpolung addition products in good to excellent yields by a similar reaction mechanism. For sulfur nucleophiles, the addition reactions with ethyl 2-methyl-2,3-butadienoate proceeded by a different mechanism.

Phosphane-mediated cyclizations between α-keto nitriles and methylidenemalononitriles, producing highly functionalized cyclopropanes in good to excellent yields, are reported. The presence of strongly electron-withdrawing cyano groups directly bound to the ketone carbonyl groups is believed to play a critical role in these transformations.