Catalyst-controlled selective mono-/dialkylation of 2-aryl-4(3H)-quinazolinones

Tandem C-C/C-N Bond Formation via Rh(III)-Catalyzed α-Fluoroalkenylation and Sequential Annulation of 2-Arylquinazolinones and gem-Difluorostyrenes

An efficient method of Rh(III)-catalyzed coupling reaction between 2-arylquinazolinones and gem-difluorostyrenes has been developed. In this work, two diverse structures of monofluoroalkenes and isoindolo[1,2-b]quinazolin-10(12H)-one derivatives were respectively synthesized by controlling the amount of additives (Ca(OH)₂ and AgNTf₂) to achieve controlled stepwise breaking of the C-F bonds of gem-difluorostyrenes. This reaction has the characteristics of a wide range of substrates and good functional group tolerance. Meanwhile, several control experiments were conducted and a plausible mechanism was proposed.

Iridium(III)-Catalyzed C(3)-H Alkylation of Isoquinolines via Metal Carbene Migratory Insertion

An Ir(III)-catalyzed C(3)-H alkylation of N-acetyl-1,2-dihydroisoquinolines with diverse acceptor-acceptor diazo compounds has been achieved under a single catalytic system via metal carbene migratory insertion. Moreover, further synthetic transformations of the alkylated products such as aromatization, selective decarboxylation, and decarbonylation lead to the formation of several synthetically viable isoquinoline derivatives having immense potentials.

Synthesis of oxazolidinones through ring-opening and annulation of vinylene carbonate with 2-pyrrolyl/indolylanilines under Rh(III) catalysis

Herein, we have developed a rhodium-catalyzed C-H functionalization and subsequent intramolecular ring-opening/cyclization of vinylene carbonate with 2-pyrrolyl/indolylanilines, which leads to oxazolidinones in moderate to good yields. In this transformation, vinylene carbonate only eliminates one oxygen atom rather than -CO₃ or CO₂. Furthermore, some control experiments are conducted to elucidate the reaction mechanism.

Transition-Metal-Catalyzed C-H Bond Functionalization of Arenes/Heteroarenes via Tandem C-H Activation and Subsequent Carbene Migratory Insertion Strategy

The past decade has witnessed tremendous developments in transition-metal-catalyzed C-H bond activation and subsequent carbene migratory insertion reactions, thus assisting in the construction of diverse arene/heteroarene scaffolds. Various transition-metal catalysts serve this purpose and provide efficient pathways for an easy access to substituted heterocycles. A brief introduction to metal-carbenes has been provided along with key mechanistic pathways underlying the coupling reactions. The purpose of this review is to provide a concise knowledge about diverse directing group-assisted coupling of varied arenes/heteroarenes and acceptor-acceptor/donor-acceptor diazo compounds. The review also highlights the synthesis of various carbocycles and fused heterocycles through diazo insertion pathways, via C-C, C-N and C-O bond forming reactions. The mechanism usually involves a C-H activation process, followed by diazo insertion leading to subsequent coupling.

Ru(ii)-Catalyzed C-H addition and oxidative cyclization of 2-aryl quinazolinones with activated aldehydes

The ruthenium(ii)-catalyzed cross-coupling reaction between 2-aryl quinazolinones and activated aldehydes is described. This method enables the site-selective hydroxyalkylation under redox-neutral conditions. Moreover, this protocol provides a facile access to various tetracyclic isoindoloquinazolinones by using Cu(OAc)₂ as an external oxidant via C-H addition and subsequent intramolecular cyclization. A wide substrate scope and a high level of chemoselectivity as well as broad functional group tolerance are observed.

C–H functionalization of quinazolinones by transition metal catalysis

Quinazolinone and its derivatives are an important class of heterocyclic scaffolds in pharmaceuticals and natural products. This review provides the recent research advances in the transition metal catalyzed selective C–H bond functionalization of quinazolinone.