Five‐Membered Heterocycles: Pyrrole and Related Systems

Recent Advances on Pyrrole Synthesis through Different Annulation Modes

“…Using carbohydrates and primary amines as substrates, Koo and co-workers [47] also published a one-pot conversion method for the synthesis of pyrrole-2-carbaldehydes in the presence of oxalic acid as promoter, and applied it to the synthesis of 2-benzyl and 2-methylpyrrolo [1,4]oxazin-3one, lobechine and (-)-hanishin (Scheme 24).…”

“…Pyrrole, as a basic five-membered aromatic heterocycle, has been recognized as one of the most important heterocycles due to its extensive utilities. [1][2][3][4] Since its first detection by Runge in 1834 and structural confirmation by von Bayer in the 1870s, pyrrole has been found not only in a variety of biological contexts, but also in lots of natural products, man-made bioactive molecules and functional materials. [5][6][7][8][9][10] First of all, it is the basic component of a series of porphyrin-derived pigments, like chlorophylls, hemes and coenzyme F430, which are vital for nearly all organisms (Figure 1).…”

Synthesis of 3-[(4-Nitrophenyl)thio]-Substituted 4-Methylene-1-pyrrolines from N-Propargylic β-Enaminones

“…Pyrroles, as one of the most abundant and important class of heterocyclic compounds, appear frequently in the structures of many natural products, bioactive compounds, and functional molecules . Indeed, pyrroles are precious scaffolds for pharmaceutical and medicinal research since they exhibit remarkable biological properties such as analgesic, antiallergic, anticonvulsant, antidepressant, antidiabetic, antihyperlipidemic, antiinflammatory, antimicrobial, antifungal, antiviral, cholesterol-reducing, and antitumor properties .…”

One-pot sequential multicomponent reaction between in situ generated aldimines and succinaldehyde: facile synthesis of substituted pyrrole-3-carbaldehydes and applications towards medicinally important fused heterocycles

“… 2 In addition, functionalized pyrroles have shown wide applications in agrochemicals and flavor components, dyes, and functionalized materials. 3 Over the past few decades, a number of elegant methods to access functionalized pyrroles have been reported, which includes classical methods, 4 cycloadditions, 5 multi-component, 6 metal-catalyzed reactions, 7 and several others. 8 Despite the extensive efforts, the synthesis of C3-functionalized pyrroles is probably the most difficult task and required a special strategy.…”