A highly diastereoselective three-component inverse-electron-demand aza DielsâAlder reaction assisted by per(poly)fluoro-alkanesulfinamides is presented, providing a broad spectrum of highly functionalized piperidine derivatives with excellent endo/exo and facial diastereoselectivities. The electron-withdrawing perfluoroalkyl groups are crucial for the success of this reaction under mild conditions and facilitate monitoring the process and stereoselectivities of the reaction. The synthetic potential of these cycloadducts is also highlighted.
The first nickel-catalyzed CH trifluoromethylation of pyridineN-oxides with Togni’s reagent has been achieved. Trifluoromethylation proceeds smoothly under mild conditions with moderate functional group compatibility. Notable advantages of this method include the using of low cost of nickel catalyst, and its simple convenient operation.
Iodomethane is usually used as an electrophilic methylation reagent. Herein, we report its use as a C1 organocatalyst for the aerobic ortho-selective trifluoromethylation of pyridines in the absence of a transition metal. Trifluoroacetic acid (TFA) was employed as an inexpensive, readily available trifluoromethyl source. The reaction efficiently produced a variety of trifluoromethylation products,