Substrate-Controlled Selectivity Switch in the Three-Component Coupling Involving Arynes, Aromatic Tertiary Amines, and CO₂

Abstract

The transition-metal-free multicomponent coupling involving arynes, aromatic tertiary amines, and CO is reported. The reaction exhibits switchable selectivity depending on the electronic nature of the aromatic amines used. With amines bearing electron-releasing/neutral groups as the nucleophilic trigger, the reaction afforded 2-arylamino benzoates via a nitrogen to oxygen alkyl group migration. Employing electron-deficient amines in the reaction furnished 2-aminoaryl benzoates proceeding via the aryl to aryl amino group migration resembling a Smiles rearrangement.

Aryne-Based Multicomponent Coupling Reactions

“…46 Biju and co-workers reported that MCRs of arynes with tertiary aromatic amines and carbon dioxide formed zwitterionic intermediate 33, which could undergo either N→O alkyl or aryl group migration to generate anthranilic acid derivatives (Scheme 12). 47…”

Discussion Addendum for: The Direct Acyl-Alkylation of Arynes. Preparation of Methyl 2-(2-acetylphenyl)acetate

“…The Biju group disclosed an amino-carboxylation of arynes using aniline derivatives (Scheme 3). 9 This method offers a divergent approach for the synthesis of differentially substituted acyl-aminated arenes depending on the electronics of the aniline ring.…”

Multicomponent Reaction of Phosphines, Benzynes, and CO2: Facile Synthesis of Stable Zwitterionic Phosphonium Inner Salts

“…In 2008, Yoshida and co-workers documented a concise three-component coupling of benzynes, secondary amines, and CO 2 , furnishing anthranilic acids directly (Scheme , eq c). Interestingly, with the introduction of aromatic tertiary amines to the reaction, Biju and co-workers developed a novel substrate-controlled switchable MCR involving benzynes and CO 2 , delivering two different types of 2-aminoaryl benzoates selectively (Scheme , eq c). Recently, Jiang and co-workers disclosed a new three-phase four-component coupling reaction involving benzynes.…”