Diastereoselective Synthesis of Polysubstituted Pyrrolidines/Dihydropyrroles: Photochemical Properties of Polysubstituted Pyrroles

Abstract

Polysubstituted pyrrolidines/dihydropyrroles and the corresponding pyrrole derivatives were synthesized via three‐component/pseudo four‐component reaction of chalcone, benzylamine and benzaldehyde, and followed by DDQ oxidation. When exposed to UV light under aerobic conditions, the prepared pyrrole derivatives were found to be light‐sensitive and undergo oxidative ring‐opening reaction to yield the corresponding enamides.

Copper Catalyzed Heteroannelation Reaction between 4‐Thiazolidinones and O‐Acetyl Oximes to Synthesize 2,5‐Diphenyl‐3‐(Pyrimidin‐2‐yl)‐3,4‐Dihydro‐2H‐Pyrrolo‐[2,3‐d]‐Thiazole

“…Many classical reactions, like Hantzsch pyrrole synthesis, Clauson-Kaas synthesis, Paal-Knorr synthesis, Piloty-Robinson synthesis, etc., are widely explored for the synthesis of pyrrole nucleus. [9][10][11][12][13] A novel example of newly emerged tool in pyrrole synthesis is cascade annulation, which involves activation of one or more C À H bonds is an important breakthrough. [14,15] New synthetic strategies involving transition-metal catalysis have been extensively studied.…”

“… [7,8] Therefore, constant attempts have been made by researchers to find various routes and tactical approaches to get pyrrole and pyrrole containing analogues. Many classical reactions, like Hantzsch pyrrole synthesis, Clauson‐Kaas synthesis, Paal‐Knorr synthesis, Piloty‐Robinson synthesis, etc., are widely explored for the synthesis of pyrrole nucleus [9–13] . A novel example of newly emerged tool in pyrrole synthesis is cascade annulation, which involves activation of one or more C−H bonds is an important breakthrough [14,15] .…”

Gold-catalyzed formal (3 + 2) and (4 + 2) cycloadditions of alkynes to highly functionalized dihydropyrroles and tetrahydropyridines

“…For instance, the 2,3-dihydropyrrole product 3a could be readily converted into the corresponding pyrrole 4 by a simple DDQ oxidation. 10 An intramolecular aldol condensation reaction 11 could be applied to the cycloadduct 3n, leading to the hexahydroisoquinoline derivative 5, which exists as core skeletons of various biologically important molecules. 12 To gain more insight into this gold-catalyzed formal cycloaddition reaction, we performed several mechanism exploration experiments.…”