Recent advances in the cyclization reactions of pyridinium 1,n-zwitterions (n = 4 and 5): scope and mechanism

Abstract

Nitrogen- and sulfur-containing heterocyclic compounds widely existed in bioactive natural products and drug molecules with unique bioactivity. The synthesis of nitrogen-and sulfur-containing hybrids had always been a hot topic in...

NBS-Promoted Synthesis of Thiocyanated Aminomaleimides and Site-Selective Intramolecular Cyclization Access to 1,4-Benzothiazepines via S–CN Bond Cleavage

“…Nitrogen- and sulfur-containing heterocycles represent an important class of structurally privileged molecules that are frequently found in bioactive natural products, pharmaceuticals, and functional organic materials . Among them, benzothiazepines, especially 1,4-benzothiazepines, make up a representative class of S/N-seven-membered heterocycles that have received significant attention because of their broad biological activities.…”

Pd-Catalyzed Decarbonylative sp2 C–H Arylation: Construction of Five- and Six-Membered (Hetero)Cyclic Compounds

“…all have cyclic structures (Scheme A). Thus, their efficient construction always is one of the most important research fields and great advances have been made during the past decades. , Among the established protocols, the transition-metal-catalyzed intramolecular sp 2 C–H arylation stands out and attracts our attention (Scheme B) . This type of reaction depends on the transformation of organohalides and takes place through oxidative addition, intramolecular C–H cleavage, and subsequent reductive elimination.…”

Bisphosphonium salt catalyzed [3 + 2] annulation of N-tosylimino(iso)quinolinium ylides with aryl olefins under blue LED irradiation

“…The synthesis of N-heterocyclic compounds is an extremely important branch of heterocyclic chemistry, and the study of these compounds has become a long-term concern due to their widespread presence in natural products, pharmaceutically active components, and functional materials. 1–3 Pyrazole[5,1-α]isoquinoline and pyrazole[1,5-α]quinoline are critical structural motifs widely present in biologically active molecules, such as Aurora A inhibitor I , CB1 cannabinoid receptor antagonist II , dopamine D4 receptor antagonist III , anti-tumour agent IV , phosphodiesterase 10A inhibitor V , anti-proliferative compound VI , and GPR109A agonist agent VII (Fig. 1).…”