Triphenylphosphine‑<i>m</i>‑sulfonate/Carbon Tetrabromide as an Efficient and Easily Recoverable Catalyst System for Friedel–Crafts Alkylation of Indoles with Carbonyl Compounds or Acetals

A solid complex, conveniently prepared from commercially available sodium triphenylphosphine-<i>m</i>-sulfonate (TPPMS) and carbon tetrabromide, can be used as an easily recoverable and reusable catalyst system for Friedel–Crafts alkylation of indoles with carbonyl compounds or acetals to produce bis­(indolyl)­alkane products (BIAs)

Oxidative Povarov Reaction via sp³ C–H Oxidation of <i>N</i>‑Benzylanilines Induced by Catalytic Radical Cation Salt: Synthesis of 2,4-Diarylquinoline Derivatives

Oxidative Povarov reaction of <i>N</i>-benzylanilines was realized under catalytic radical cation salt induced conditions. The mechanism studies revealed that a radical intermediate was involved in this catalytic oxidation. This method provides a new way to synthesize 2,4-diarylquinoline derivatives

Catalytic Radical Cation Salt Induced C_sp³–H Functionalization of Glycine Derivatives: Synthesis of Substituted Quinolines

A domino C_sp³–H functionalization of glycine derivatives was achieved under catalytic radical cation salt induced conditions, producing a series of quinolines. The proposed mechanism shows that a peroxyl radical cation, which is generated by the coupling between O₂ and TBPA^+•, might be involved to initiate the catalytic oxidation

Approach to Construct Polysubstituted 1,2-Dihydronaphtho[2,1‑<i>b</i>]furans and Their Aerobic Oxidative Aromatization

Triarylaminium salt was disclosed as an efficient initiator for the novel Friedel–Crafts alkylation/annulation cascade reaction between chalcone epoxides and 2-naphthols to construct polysubstituted 1,2-dihydronaphtho­[2,1-<i>b</i>]­furans. The DDQ/NaNO₂/O₂ catalytic system was first applied to the aerobic oxidative aromatization of heterocycles, and a simple and efficient one-pot tandem FC alkylation/annulation/aerobic oxidative aromatization procedure was also developed for the synthesis of complex naphtho­[2,1-<i>b</i>]­furans

Aerobic Oxidative Mannich Reaction Promoted by Catalytic Amounts of Stable Radical Cation Salt

A catalytic amount of triarylaminium salt is demonstrated to be an efficient initiator for oxidative Mannich reaction of tertiary amines and nonactivated ketones under mild neutral conditions. Air is essential for this reaction and acts as a terminal oxidant. Metal catalysts, acid or base additives, and stoichiometric amounts of chemical oxidants are all avoided in this methodology. Six examples of intramolecular cyclized products are also delivered

Active sp³ C–H Bond Oxidation Initiated sp³–sp² Consecutive C–H Functionalization of <i>N</i>‑Arylglycine Amides: Construction of Isatins

In the presence of catalytic triarylamine radical cation, an sp³–sp² consecutive C–H functionalization of <i>N</i>-arylglycine amides was achieved, providing a series of isatin derivatives in high yields. In this transformation, the initial aerobic oxidation of the relatively active sp³ C–H bonds triggered the following intramolecular cyclization, in which the aniline group was employed as a removable auxiliary group to enable the consecutive process

Radical Cation Salt-Promoted Catalytic Aerobic sp³ C–H Oxidation: Construction of Quinoline-Fused Lactones and Lactams

A direct construction of quinoline-fused lactones and lactams was achieved by sp³ C–H bond oxidation of <i>N</i>-aryl glycine esters and amides under catalytic radical cation salt-induced conditions. These polycyclic products are formed in a single step from readily accessible starting materials, and this method provides a new synthetic approach to this class of heterocycles

Approach to Construct Polysubstituted 1,2-Dihydronaphtho[2,1‑<i>b</i>]furans and Their Aerobic Oxidative Aromatization

Triarylaminium salt was disclosed as an efficient initiator for the novel Friedel–Crafts alkylation/annulation cascade reaction between chalcone epoxides and 2-naphthols to construct polysubstituted 1,2-dihydronaphtho­[2,1-<i>b</i>]­furans. The DDQ/NaNO₂/O₂ catalytic system was first applied to the aerobic oxidative aromatization of heterocycles, and a simple and efficient one-pot tandem FC alkylation/annulation/aerobic oxidative aromatization procedure was also developed for the synthesis of complex naphtho­[2,1-<i>b</i>]­furans

Approach to Construct Polysubstituted 1,2-Dihydronaphtho[2,1‑<i>b</i>]furans and Their Aerobic Oxidative Aromatization

Triarylaminium salt was disclosed as an efficient initiator for the novel Friedel–Crafts alkylation/annulation cascade reaction between chalcone epoxides and 2-naphthols to construct polysubstituted 1,2-dihydronaphtho­[2,1-<i>b</i>]­furans. The DDQ/NaNO₂/O₂ catalytic system was first applied to the aerobic oxidative aromatization of heterocycles, and a simple and efficient one-pot tandem FC alkylation/annulation/aerobic oxidative aromatization procedure was also developed for the synthesis of complex naphtho­[2,1-<i>b</i>]­furans

Approach to Construct Polysubstituted 1,2-Dihydronaphtho[2,1‑<i>b</i>]furans and Their Aerobic Oxidative Aromatization

Triarylaminium salt was disclosed as an efficient initiator for the novel Friedel–Crafts alkylation/annulation cascade reaction between chalcone epoxides and 2-naphthols to construct polysubstituted 1,2-dihydronaphtho­[2,1-<i>b</i>]­furans. The DDQ/NaNO₂/O₂ catalytic system was first applied to the aerobic oxidative aromatization of heterocycles, and a simple and efficient one-pot tandem FC alkylation/annulation/aerobic oxidative aromatization procedure was also developed for the synthesis of complex naphtho­[2,1-<i>b</i>]­furans