Visible light-induced functionalization of indazole and pyrazole: a recent update

Abstract

Indazole and pyrazole are endowed as a prodigious class of heterocycles having versatile uses in medicinal as well as industrial chemistry. Considering sustainable approaches, recently, photocatalysis is an indispensable tool...

Excited-state cobaloxime catalysis enabled scalable oxidant-free dehydrogenative C–H phosphinoylation of undirected heterocycles

“…Encouraged by the above unprecedented reactivity, we tested the reactivity of some π-extended N-heterocycles and polycyclic aromatic hydrocarbons under the standard conditions to explore the synthetic potential of this cobaloxime catalyzed phosphinoylation reaction considering the potential utility of N-heterocycles and polycyclic aromatic hydrocarbons in pharmaceutical chemistry. 16 As shown in Table 4, highly regioselective phosphinoylations of imidazo[2,1- b ]thiazoles ( 6a and 6b ), indazole ( 6c ), indolizine ( 6d and 6e ) and quinoline ( 6f ) with moderate yields were successfully achieved. Unfortunately, 1-methyl-1 H -indole and benzo[ d ]thiazole were not compatible with this reaction (for details see the ESI, Fig.…”

Synthesis of Pincer type carbene and their Ag(I)-NHC complexes, and their Antimicrobial activities

“…Additionally, they may be stabilized as ligands in different transition-metal complexes [9], and the synthesis of these pNHC complexes received interest and were prepared by many applications [10]. One feasible route for the adjustment of complexes with protic pNHC ligands is the oxidative supplementation of [11] N-alkyl halogen azoles [12] or unsubstituted azoles to different kind low-valent transition metals, such as Ni, Pd, and Pt. As a proton resource, this reaction gives pNHC complexes of type I, as an example [13].…”

Recyclable ZnIn2S4 Microspheres for Photocatalytic Azolation of N-Heterocycles

“…Azole is a class of important heterocyclic moieties in biologically active compounds such as drugs and pesticides. − Considering the importance of azoles, the application of azoles as nitrogen sources for the construction of the C–N bond via the cross-coupling reaction of C–H and N–H is a straightforward strategy for the functionalization of heterocycles. − In the conventional thermochemical oxidative coupling procedures, strong oxidants or elevated temperatures are generally required. , For example, the C–H azolation of quinoxalin-2­(1 H )-ones needs a stoichiometric amount of (diacetoxy)­iodobenzene (PIDA) as an oxidant, , which generates large amounts of wastes after the reaction. On the other hand, in the recently developed photochemical or electrochemical procedures, homogeneous photocatalysts or supporting electrolytes could not be reused and recycled. − In this context, we herein disclosed a simple, efficient, and recyclable heterogeneous ZnIn 2 S 4 -photocatalyzed C–H azolation reaction under visible light (456 nm) at room temperature using air as a mild oxidant.…”