I₂/TBHP-Mediated Oxidative Coupling of Amino-Based Bisnucleophiles and Isocyanides: Access to 2-Aminobenzoxazinones, 2-Aminobenzoxazines, and 2-Aminoquinazolines under Metal-Free Conditions

Abstract

An I 2 /tert-butyl hydroperoxide (TBHP)-mediated oxidative coupling reaction of isocyanides with amino-based bisnucleophiles is described for the synthesis of 2-aminobenzoxazinones, 2-aminobenzoxazines, and 2-aminoquinozolines in moderate to excellent yields. Furthermore, this method provides a simple and practical method to construct potential functionalized biologically active molecules.

Pd/C-Catalyzed Carbonylative Synthesis of 2-Aminobenzoxazinones from 2-Iodoaryl Azides and Amines

“…Hence, the development of new procedures for the synthesis of 2-amino-substituted benzoxazinones has attracted a lot of attention over the past decades. Ordinary methods for constructing these heterocyclic compounds are based on 2-aminobenzoic acid derivatives; however, some procedures need to be performed in the presence of concentrated acid or toxic catalyst or under oxidative conditions (Scheme ). An alternative procedure using palladium-catalyzed carbonylation of 1,1-disubstituted 3-phenylureas or palladium-catalyzed cross-coupling/cyclization of 2-azidobenzoic acids with isocyanides has been developed as well …”

I2/TBHP Reagent System: A Modern Paradigm for Organic Transformations**

“…In addition, the methodology was applied to the late‐stage modification of the bioactive compound (Scheme 62). [118] Mechanism (Scheme 63) first involves the 1,1‐ addition of iodine to isocyanide to give intermediate A which then reacts with 2‐ aminobenzoic acid to generate intermediate B with the loss of HI. In order to complete the cycle, HI is oxidized by TBHP to release iodine.…”

Iodine-Catalyzed Regioselective Oxidative Cyclization of Aldehyde Hydrazones with Electron-Deficient Olefins for the Synthesis of Mefenpyr-Diethyl

“…In recent years, metal-free catalyzed oxidative C–H functionalization has been gained considerable attention due to its low costs and the formation of environmentally acceptable byproducts. − Molecular iodine, which possesses various oxidation states and mild redox potential, has been widely utilized in oxidative coupling reactions. − Furthermore, the combination of the iodine/peroxide mediated oxidative coupling reactions has been investigated to some extent. − Despite the compelling progress, the examination of direct catalytic transformation via a iodine catalyzed strategy for the construction of privileged heterocyclic compounds is still promising. Inspired by our previous work, − and literature reports, we herein report a I 2 -catalyzed pyrazoles synthesis by an oxidative radical relay strategy.…”