Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• acid catalysts and transition metal catalysts. The goal of this review is to summarize the synthesis of various N-substituted pyrrole derivatives using a modified Clauson–Kaas reaction under diverse conventional and greener reaction conditions. Keywords: catalyst; Clauson–Kaas pyrrole synthesis; 2,5

• -dimethoxytetrahydrofuran; green synthesis; microwave-assisted reaction; N-substituted pyrrole; Introduction Heterocyclic compounds are the most explored molecules in organic chemistry in terms of their synthesis and various applications. Among the diverse heterocyclic compounds, N-containing heterocycles are found in

• are desired in light of growing environmental concerns. As a result, this review will explain various green chemistry approaches to synthesize N-substituted pyrroles. Although, Wynn [54] summarized several Clauson–Kaas protocols for the synthesis of N-substituted pyrrole derivatives. However, a

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• a long gap, in 2006, Takano and Seki prepared a PLPy(Pd) electrode coated with a chiral poly-(N-substituted pyrrole) film having ʟ-(+)-lactic acid moieties as the optically active groups and further incorporated with palladium metal [27]. Thus prepared electrodes 21 were used for the

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• , triazolo[1,2-a]indazoletrione derivatives, tetrasubstituted imidazole derivatives, aromatic/aliphatic sulfide derivatives, and N-substituted pyrrole derivatives. These catalysts were used in cellulose hydrolysis, cellobiose hydrolysis, production of fatty acid ethyl ester, the transesterification of

• derivatives. The synthetic route for MWCNT-SO3H and its catalytic application for the synthesis of N-substituted pyrrole derivatives. The sulfonic acid-functionalized polymers (P-SO3H) covalently

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• mechanochemical Paal–Knorr pyrrole synthesis using a solid bio-sourced acid like citric acid. Using substituted aniline, benzyl or aliphatic amine and 1,4-diketo compounds in presence of 1 mol % citric acid under ball-milling afforded the desired N-substituted pyrrole with quantitative yield (Scheme 34) [142

2-(1-Hydroxypropyn-2-yl)-1-vinylpyrroles: the first successful Favorsky ethynylation of pyrrolecarbaldehydes

• A. V. Ivanov,
• V. S. Shcherbakova,
• I. A. Ushakov,
• L. N. Sobenina,
• O. V. Petrova,
• A. I. Mikhaleva and
• B. A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 228–232, doi:10.3762/bjoc.11.25

• , incapable of the above ionization, might normally undergo the Favorsky reaction. Indeed, this proves to be true. This is a concise report on the first successful base-mediated ethynylation of 1-vinylpyrrole-2-carbaldehydes 1a–j with acetylene. These N-substituted pyrrole-2-carbaldehydes have been chosen for

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

• Sudipta Pathak,
• Kamalesh Debnath and
• Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

• substantial retention of catalytic activity and efficiency of SSA even after repeated application (Figure 2). Conclusion In conclusion, a facile and convenient methodology has been developed for the synthesis of a diverse range of N-substituted pyrrole-fused isocoumarins in presence of the solid-supported