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

• ) in acetic acid, affording ethyl arylpyrrolylpropionates 5 in 59–95% and pyrrole 7 in 78% yield. Representative examples of compounds 5 are shown in Scheme 3. Furthermore, these N-substituted pyrroles were used to prepare various aryl-substituted pyrrolizine and indolizine derivatives. In 2014, Kumar

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

Dienophilic reactivity of 2-phosphaindolizines: a conceptual DFT investigation

• Nosheen Beig,
• Aarti Peswani and
• Raj Kumar Bansal

Beilstein J. Org. Chem. 2022, 18, 1217–1224, doi:10.3762/bjoc.18.127

• , which was named as 2-phosphaindolizine perceiving it to result from a formal CH/P exchange at the 2-position of indolizine (2) (Figure 1) [1]. Subsequently a good library of these interesting compounds became accessible [1]. The methodology could be extended successfully to the synthesis of 1,3,4

• energy minimum with no imaginary frequency. Chemical reactivity descriptors were calculated as follows: Structures of 2-phosphaindolizine (1) and indolizine (2). Structures of 1-aza-2-phosphaindolizines 3, 3-aza-2-phosphaindolizines 4, and 1,3-diaza-2-phosphaindolizine (5). Transfer of the

Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• at the double bond underwent cyclization as the result of intramolecular interception of the rhodium carbene, which led to the formation of indolizine [6] or 2H-chromene [7] derivatives, respectively (Figure 1). At the same time, Rh2(esp)2-catalyzed reactions of DAS with nitriles and carbonyl

Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• development of an enantioselective aza-Sakurai cyclization (Scheme 12) [70]. In this transformation, a chiral thiourea catalyst 58 with a dibenzothiophene functionality serves as a dual H-bond donor and Lewis base to facilitate the cyclization of hydroxylactams 56. Thus, indolizine and quinolidizine

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• natural products as well as compounds of commercial interest as medications. Synthetic strategies to molecules as simple as amino alcohols to as complex as indolizine alkaloids will be discussed with a special focus on stereoselectivities of key transformations. Whenever possible biological activities of

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

Sydnone C-4 heteroarylation with an indolizine ring via Chichibabin indolizine synthesis

• Florin Albota,
• Mino R. Caira,
• Constantin Draghici,
• Florea Dumitrascu and
• Denisa E. Dumitrescu

Beilstein J. Org. Chem. 2016, 12, 2503–2510, doi:10.3762/bjoc.12.245

• Pharmacy, University Ovidius, Aleea Universitatii 1, Constantza, Romania 10.3762/bjoc.12.245 Abstract The synthesis of sydnones heteroarylated at C-4 with an indolizine was achieved by Chichibabin (Tschitschibabin) indolizine synthesis starting from the corresponding sydnone-N-pyridinium bromides. The

• ; Chichibabin synthesis; indolizine; pyridinium N-ylide; sydnone; Introduction In recent decades, interest in the syntheses of biheteroaryls has been focused on the creation of new hetaryl–hetaryl C(sp2)–C(sp2) bonds, in particular through cross-coupling reactions. These reactions are catalyzed by palladium or

• sydnone ring. From a survey of the literature data [6][7][8][9][10][11][12][13][14][15] and based on our previous findings [16][17][18][19] it was concluded that the heterocycle in the pyrroloazine series most suitable for this study would be indolizine (2). Indolizine or pyrrolo[1,2-a]pyridine (2) and

C–H bond halogenation catalyzed or mediated by copper: an overview

• Wenyan Hao and
• Yunyun Liu

Beilstein J. Org. Chem. 2015, 11, 2132–2144, doi:10.3762/bjoc.11.230

• -component annulation intermediate 60 which led to the formation of indolizine 61 via oxidative decarboxylation. And the bromination of 61 took place in situ to give products 59 via an unprecedented dehydrogenative bromination (Scheme 19). By making use of the copper-mediated arene C–H bond halogenation

Indolizines and pyrrolo[1,2-c]pyrimidines decorated with a pyrimidine and a pyridine unit respectively

• Marcel Mirel Popa,
• Emilian Georgescu,
• Mino R. Caira,
• Florentina Georgescu,
• Constantin Draghici,
• Raluca Stan,
• Calin Deleanu and
• Florea Dumitrascu

Beilstein J. Org. Chem. 2015, 11, 1079–1088, doi:10.3762/bjoc.11.121

• structures of two of the starting materials, 4-(2-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine, are also reported. Keywords: indolizine; nitrogen heterocycles; N-ylide; 4-pyridylpyrimidine; pyrrolo[1,2-c]pyrimidine; Introduction Two heteroarenes linked through a single bond [1] proved to be versatile

• other possible indolizine (14A) was observed also in the bulk reaction mass in low to medium quantities but was not recovered, further work being in progress to investigate this aspect. Due to the fact that the salts 13 are not easy to work up we ran the reaction in a multicomponent approach and only in

• (Scheme 3). In some cases we carried out the reaction in two steps by isolating the salts 15, the yields being similar. The 1H NMR spectra of the indolizines 16a–f confirm their structure. All the atoms in the indolizine moiety were assigned by COSY and HETCOR experiments. The main features are the signal

Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromothiophene derivatives

• Fatma Belkessam,
• Aidene Mohand,
• Jean-François Soulé,
• Abdelhamid Elias and
• Henri Doucet

Beilstein J. Org. Chem. 2014, 10, 2912–2919, doi:10.3762/bjoc.10.309

• with 2,5-dibromothiophene in the presence of Pd(OAc)2 (5 mol %) and PCy3 (10 mol %) catalyst to afford the 2,5-di(pyrrolyl)thiophene in 59% yield [40]. Finally, an indolizine was also successfully coupled with 2,5-dibromothiophene in 47% yield in the presence of Pd(OAc)2 as catalyst [41]. To our

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• ]. An excess of reagent gives bis-(SCF3) pyrrole derivatives as shown in Scheme 14. Condensed pyrroles also react readily with CF3SCl. Indole undergoes substitution, as expected, at the 3-position [80], while indolizine and some of its derivatives give 1,3-bis (SCF3)-substituted products, in some cases

• , in quantitative yield [81]. It is interesting to note that not only hydrogen, but also an acetyl group in the 1-position is substituted (Scheme 15). However, no reaction occurs when there are two electron-withdrawing groups in the five-membered indolizine ring (e.g. R = Ph, and X = COPh or NO2). By

• contrast, in the case of 1-benzyl-2-methyl indolizine [81] both the pyrrole and the aromatic ring of the benzyl group undergo trifluoromethylsulfanylation. Only N-substitution occurs in the case of carbazole [80]. N-Methylpyrrole can be variously substituted depending on the conditions as illustrated in

Synthesis of (–)-Indolizidine 167B based on domino hydroformylation/cyclization reactions

• Giuditta Guazzelli,
• Raffaello Lazzaroni and
• Roberta Settambolo

Beilstein J. Org. Chem. 2008, 4, No. 2, doi:10.1186/1860-5397-4-2

• -pot intramolecular cyclization providing a general approach to the indolizine nucleus. Background Indolizidine alkaloids are widely diffused in nature and have attracted considerable attention because of their varied range of pharmaceutical application. Indolizidine 167B (Figure 1), one of the

• reaction mixture while the branched one 2b was in 13% (GC-MS control) with respect to the indolizine structure (Scheme 2). While at room temperature and high pressure the 2a/2b ratio is largely favorable to the branched aldehyde (29/71) [21], under the above conditions (high temperature and low pressure) a

• describe here a new synthesis of optically active (–)-Indolizidine 167B based on regioselective hydroformylation/intramolecular cyclization reactions which provides a general approach to the indolizine nucleus. It is a multi-step domino process which starts with the interconversion of the isomeric rhodium

Efficient synthesis of 5-substituted 2-aryl- 6-cyanoindolizines via nucleophilic substitution reactions

• Eugene V. Babaev,
• Natalya I. Vasilevich and
• Anna S. Ivushkina

Beilstein J. Org. Chem. 2005, 1, No. 9, doi:10.1186/1860-5397-1-9

• natural alkaloids contain in their structure a saturated (swainsonine) or aromatic (camptothecin) indolizine moiety. While the chemistry of indolizines has been widely investigated[1] the chemistry of 5-substituted indolizines remains very poor because there are only a few reliable ways for their