Synthesis of isoquinolone via rhodium(III)-catalyzed C-H activation with 1,4,2-dioxazol-5-ones as oxidizing directing group

Transition metal catalysed direct construction of 2-pyridone scaffolds through C-H bond functionalizations

Substituted 2-pyridone is one of the most frequent scaffolds among nitrogen-containing bioactive natural products, pharmaceuticals and organic materials. Besides the classical syntheses to construct this class of molecules, retrosynthetically more straightforward approaches based on transition metal catalysed C-H bond functionalizations have been explored recently. In this review, we have summarized the recent progress in the direct transition metal catalysed construction of substituted 2-pyridone scaffolds via site-selective C-H bond functionalizations.

Synthesis of Isoquinolones by Sequential Suzuki Coupling of 2-Halobenzonitriles with Vinyl Boronate Followed by Cyclization

A novel, facile, and expeditious two-step synthesis of 3,4-unsubstituted isoquinolin-1(2H)-ones from a Suzuki cross-coupling between 2-halobenzonitriles and commercially available vinyl boronates followed by platinum-catalyzed nitrile hydrolysis and cyclization is described.

Rh(III)-Catalyzed three-component cascade annulation to produce the N-oxopropyl chain of isoquinolone derivatives

Developing powerful methods to introduce versatile functional groups at the N-substituents of isoquinolone scaffolds is still a great challenge. Herein, we report a novel three-component cascade annulation reaction to efficiently construct the N-oxopropyl chain of isoquinolone derivatives via rhodium(iii)-catalyzed C-H activation/cyclization/nucleophilic attack, with oxazoles used both as the directing group and potential functionalized reagents.

Palladium-catalyzed sequential acylation/annulation of indoles with acyl chlorides using primary amine as the directing group

An efficient, palladium(ii)-catalyzed, C(sp²)–H acylation/annulation of indoles with acyl chlorides for the synthesis of substituted indolo[1,2-a]quinazolines is reported.

Rhodium-catalyzed synthesis of substituted isoquinolones via a selective decarbonylation/alkyne insertion cascade of phthalimides

A rhodium-catalyzed decarbonylation/alkyne insertion cascade of phthalimides has been established. The reaction can be carried out in an operationally simple manner and provides expedient access to a series of isoquinolones in moderate to good yields. This reaction proceeded through a sequential decarbonylation/alkyne insertion/intramolecular annulation procedure and featured good functional group tolerance, ample substrate scope, and the construction of C-C and C-N bonds in one pot.

Rhodium-Catalyzed Annulative Coupling of Isothiazoles with Alkynes through N-S Bond Cleavage

A Rh(III)-catalyzed annulative coupling of 3,5-diarylisothiazoles and alkynes is reported. The N-S bond in the isothiazole ring acts as an internal oxidant to regenerate the Rh(III) species in combination with an external Cu(II) oxidant, and the corresponding 1:2 coupling products are obtained. The remarkable difference in the reaction outcome between isothiazoles and the relevant isoxazoles has been investigated by DFT calculations, revealing that the relative stability of the enolate intermediates dictates the product selectivity.