Carbocation Lewis Acid Catalyzed Redox-Neutral α-C(sp³)H Arylation of Amines

Organocatalysis in Inert C–H Bond Functionalization

“…71 In 2016, Luo and co-workers disclosed that the tritylium salt, [Ph 3 C][BArF], generated in situ could act as organic Lewis acid and promote the three-component redoxneutral α-arylation of tetrahydroisoquinoline, aldehyde, and indole to afford the desired α-substituted N-heterocyclic products in good yields (Scheme 42). 72 2.1.7. Photoredox Organocatalysis.…”

Carbocation Lewis Acid TrBF4-Catalyzed 1,2-Hydride Migration: Approaches to (Z)-α,β-Unsaturated Esters and α-Branched β-Ketocarbonyls

“…Recently, we developed latent carbocation catalysis with chiral phosphate as a counteranion of the trityl cation, which efficiently promoted the asymmetric Friedel–Crafts reaction, HDA reaction, and carbonyl-ene reaction . In addition, we also reported the tritylium salt TrBArF, in situ-generated by Ph 3 CBr and NaBArF-catalyzed redox-neutral α-C­(sp 3 )H arylation of amines and Diels–Alder reaction of β,γ-unsaturated α-ketoesters with anthracenes . In fact, Ph 3 C + -mediated C–H oxidations via a hydride abstraction mechanism are also well-known.…”

Condensation-Based Methods for the C–H Bond Functionalization of Amines

“…In 2016, Luo, Lv, and Zhang reported very similar reactions catalyzed by a Lewis acidic tritylium salt. 94 In addition, redox-neutral -arylation reactions involving THIQs were also reported by Deb, Baruah, and co-workers in 2020 using L-proline as the catalyst. 95 The Rawat group realized closely related transformations under catalyst-free conditions in a biodegradable PEG solvent.…”