Chiral molecules containing the pyrrole framework

Abstract

This review summarizes strategies by which chiral pyrroles, both simple and complex, have been prepared: strategies include formation of the pyrrolic ring using starting materials appended with chirality, as well as the attachment of chirality to a pre-formed pyrrolic ring.

Practical Pd(TFA)2-Catalyzed Aerobic [4+1] Annulation for the Synthesis of Pyrroles via “One-Pot” Cascade Reactions

“…In recent years, efficient synthetic approaches to construct organic frameworks containing pyrroles have been developed [25][26][27][28][29][30][31][32][33][34][35]. On the other hand, the transition-metal-catalyzed sp 2 C-H amination reaction is one of the most demanding procedures to form C-N bonds [36,37].…”

Mechanism of the Paal–Knorr reaction: the importance of water mediated hemialcohol pathway

“…Very recently, catalyst and solvent-free conditions have been employed to synthesize underivatized and N-substituted pyrroles by Cho et al 38 The importance of this synthetic reaction is highlighted in the synthesis of the drugs Atorvastatin (antitriglyceride), [39][40][41] Aloracetam (anti-Alzheimer's), 42 Prodiogiosin (antibacterial, anti-fungal and anti-malarial) 43, 44 and Roseophilin (antitumour) ( Figure 1). 43,[45][46][47] For example, innovative strategies are being developed for the economically viable, eco-friendly and easy bulk production of Atorvastatin using second generation synthetic procedures, which also involve the Paal-Knorr method. 48 Though the importance of the Paal-Knorr synthetic procedure was clear, very few studies were carried out to explore the mechanism of this reaction.…”

A Highly Efficient Paal-Knorr Synthesis of Chiral Pyrrole Derivatives Catalyzed by MgI2

“…吡咯衍生物是一类重要的具有显著生物活性的化 合物 [1] , 同时也是天然产物和杂环化合物合成的重要中 间体 [2,3] (如维生素 B 12 、胆色素、血红素、叶绿素、生物 碱等化合物都包含有吡咯片段 [4] ), 很多合成得到的包 含有吡咯片段的化合物都表现出了一定的抗菌 [5] 、抗病 毒 [6] 以及抗肿瘤 [7] 生物活性. 在氮原子上具有手性取代 的吡咯衍生物具有显著的生物活性, 这些吡咯衍生物在 合成与其生物活性高度相关的化合物中都是极具潜力 的活性片段.…”

“…在这些合成方法中, Paal-Knorr 反应仍 然是最重要、最简便的方法之一, 它由伯胺和 1,4-二酮 进行环合反应, 最终得到 N-取代吡咯衍生物. 近年来报道了诸多 Lewis 酸, 如 Ti(Oi-Pr) 4 [16] , ZrOCl 2 •8H 2 O [17] , Sc(OTf) 3 [18] , Bi(NO 3 ) 3 •5H 2 O [19] , ZrCl 4 [20] , (S)-2-(2,5-二甲基-1H-吡咯-1-基)丙酸甲酯(2a) [26] : [27] ( [26] (S)-2-(2,5-二甲基-1H-吡咯-1-基)-3-甲基丁酸甲酯 (2h) [26] : 丙酸甲酯(2i) [28] : 棕色油状液体; ee＝85% [HPLC 测定, …”