The three-component Povarov reaction of aldehydes (2), anilines (3), and benzyl N-vinylcarbamate 4 in the presence of 0.1 equiv of chiral phosphoric acid 5 afforded cis-2,4-disubstituted tetrahydroquinolines (1) in good yields and excellent enantiomeric excesses. The shortest synthesis of torcetrapib reported to date, which features this key three-component reaction, is documented.

In this Review, we highlight recent advances in the understanding and design of N‐functionalized pyridinium scaffolds as redox‐active, single‐electron, functional group transfer reagents. We provide a selection of representative methods that demonstrate reactivity and fundamental advances in this emerging field. The reactivity of these reagents can be divided into two divergent pathways: homolytic fragmentation to liberate the N‐bound substituent as the corresponding radical or an alternative heterolytic fragmentation that liberates an N‐centered pyridinium radical. A short description of the elementary steps involved in fragmentation induced by single‐electron transfer is also critically discussed to guide readers towards fundamental processes thought to occur under these conditions.

A photoredox-catalzyed trifluoromethylation of enecarbamates process is reported. This pathway uses Togni's reagent as the CF3 source and follows a radical/cationic pathway. Under the optimized conditions using [Ru(bpy)3(PF6)2] as the photocatalyst, a wide range of substituted enecarbamates can readily be difunctionalized by means of various O, N, and C nucleophiles.