Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• reaction gave the unsaturated compounds (47 and 48), which, upon hydrogenation in presence of Crabtree’s catalyst, gave the saturated compounds with the desired diasteroselectivity (49 and 50). In the case of nitrogen containing heterocycles, Pd(OH)2 was found to be a suitable catalyst that gave a

¹⁵N-Labelling and structure determination of adamantylated azolo-azines in solution

• Sergey L. Deev,
• Alexander S. Paramonov,
• Tatyana S. Shestakova,
• Igor A. Khalymbadzha,
• Oleg N. Chupakhin,
• Julia O. Subbotina,
• Oleg S. Eltsov,
• Pavel A. Slepukhin,
• Vladimir L. Rusinov,
• Alexander S. Arseniev and
• Zakhar O. Shenkarev

Beilstein J. Org. Chem. 2017, 13, 2535–2548, doi:10.3762/bjoc.13.250

• constants for the structure determinations of N-alkylated nitrogen-containing heterocycles in solution. This method was tested on the N-adamantylated products in a series of azolo-1,2,4-triazines and 1,2,4-triazolo[1,5-a]pyrimidine. The syntheses of adamantylated azolo-azines were based on the interactions

• -azine core with a bridgehead nitrogen atom is found in many natural products [5][6] and biologically active synthetic compounds [7][8]. The purine-like scaffold of these nitrogen-containing heterocycles is frequently used in medicinal chemistry and drug design. For example, 6-nitro-1,2,4-triazolo[5,1-c

• the unambiguous positioning of alkyl (N-adamantyl, N-tert-butyl or N-aryl) fragments in azolo-azines. The incorporation of 15N labels in nitrogen-containing heterocycles greatly facilitates the use of NMR spectroscopy for studies of molecular structures and mechanisms of chemical transformations [10

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

• aminonitriles are important synthons for the preparation of nitrogen-containing heterocycles and amino acids [119]. In 2016, Bolm and co-workers reported a mechanochemical synthesis of α-aminonitriles using benzaldehyde, benzyl amine, KCN and the milling auxiliary SiO2 to isolate 70–97% of α-aminonitriles as

N-Propargylamines: versatile building blocks in the construction of thiazole cores

• S. Arshadi,
• E. Vessally,
• L. Edjlali,
• R. Hosseinzadeh-Khanmiri and
• E. Ghorbani-Kalhor

Beilstein J. Org. Chem. 2017, 13, 625–638, doi:10.3762/bjoc.13.61

• reactions to produce various nitrogen-containing heterocycles. In this review, we highlight the most important developments on the synthesis of thiazole and its derivatives starting from N-propargylamines. This review will be helpful in the development of improved methods for the synthesis of natural and

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• the titration of L4 with TBAC [37]. Catalysts L3 and L4 were successfully applied to the asymmetric dearomatization of electron-deficient N-heteroarenes (Scheme 3). Various nitrogen-containing heterocycles such as pyridines [36], quinolines [38], isoquinolines [38], etc. were reacted with TrocCl to

New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates

• Darren L. Riley,
• Joseph P. Michael and
• Charles B. de Koning

Beilstein J. Org. Chem. 2016, 12, 2609–2613, doi:10.3762/bjoc.12.256

• stems mainly from its ability to display both ambident nucleophilic and electrophilic reactivity, properties that have frequently been exploited in the synthesis of alkaloids and other nitrogen-containing heterocycles [20][21][22][23]. The enaminone and related units that form the basis of our own

Synthesis of pyrrolo[2,1-f][1,2,4]triazin-4(3H)-ones: Rearrangement of pyrrolo[1,2-d][1,3,4]oxadiazines and regioselective intramolecular cyclization of 1,2-biscarbamoyl-substituted 1H-pyrroles

• Kkonnip Son and
• Seong Jun Park

Beilstein J. Org. Chem. 2016, 12, 1780–1787, doi:10.3762/bjoc.12.168

• nitrogen-containing heterocycles have shown intriguing activities as tankyrase inhibitors 1 [1][2], stearoyl CoA desaturase inhibitors 2 [3], Eg5 inhibitors 3 [4][5], melanin-concentrating hormone receptor (MCH)-R1 antagonists 4 [6], and CRF1 receptor antagonists 5 [7][8] (Figure 1). Notably, many patent

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• Bayreuth, Germany 10.3762/bjoc.12.148 Abstract This review highlights the biosynthesis of heterocycles in polyketide natural products with a focus on oxygen and nitrogen-containing heterocycles with ring sizes between 3 and 6 atoms. Heterocycles are abundant structural elements of natural products from

• ). This review intends to give an overview on the mechanisms involved in heterocycle formation during polyketide biosynthesis. A focus will be placed on oxygen and nitrogen-containing heterocycles due to their abundance and relevance. Although the genuine polyketide biosynthesis machinery does not harbour

• of the β-hydroxy group on the thioester of 200, resulting in the off-loaded ebelactone A (201) (Scheme 28) [163]. The β-lactone moiety of the human pancreatic lipase inhibitor lipstatin is also formed in a similar fashion. 2 Nitrogen-containing heterocycles Nitrogen-containing heterocycles are

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

• Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

• biosynthesis. The function of Dfp was discovered following the mechanistic characterisation of EpiD. Cyclisation in the biosynthesis of thiopeptides. A) Mechanism of TclM-catalysed heterocyclisation in the biosynthesis of thiocillin I. B) An overview of the various 6-membered nitrogen-containing heterocycles

A concise and efficient synthesis of benzimidazo[1,2-c]quinazolines through CuI-catalyzed intramolecular N-arylations

• Xinlong Pang,
• Chao Chen,
• Ming Li and
• Chanjuan Xi

Beilstein J. Org. Chem. 2015, 11, 2365–2369, doi:10.3762/bjoc.11.258

• : benzimidazo[1,2-c]quinazoline; (bromophenyl)iodonium salt; copper catalyst; o-cyanoaniline; quinazolin-4(3H)-imine; Ullmann N-arylation; Introduction Nitrogen-containing heterocycles are ubiquitous backbones in natural products, medicine and organic materials. In addition, they are also important ligands for

Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes

• Luke J. O’Driscoll,
• Sissel S. Andersen,
• Marta V. Solano,
• Dan Bendixen,
• Morten Jensen,
• Troels Duedal,
• Jess Lycoops,
• Cornelia van der Pol,
• Rebecca E. Sørensen,
• Karina R. Larsen,
• Kenneth Myntman,
• Christian Henriksen,
• Stinne W. Hansen and
• Jan O. Jeppesen

Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125

• incorporated into a larger conjugated system, is less common, although interest has increased in recent years. These reactions can be accomplished using a copper-mediated Ullman-type reaction, based on conditions reported by Buchwald and co-workers for the arylation of nitrogen-containing heterocycles and the

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

• Volodymyr V. Tkachenko,
• Elena A. Muravyova,
• Sergey M. Desenko,
• Oleg V. Shishkin,
• Svetlana V. Shishkina,
• Dmytro O. Sysoiev,
• Thomas J. J. Müller and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

• hydroxyaryl group as well as tricyclic nitrogen-containing heterocycles derived from salicylaldehyde have been reported as anticancer [1], antihypertensive agents [2], neuropeptide Y antagonists [3], and calcium channel blockers [4]. Fused azoloazines containing carboxamide substituents also exhibit a broad

A simple copper-catalyzed two-step one-pot synthesis of indolo[1,2-a]quinazoline

• Chunpu Li,
• Lei Zhang,
• Shuangjie Shu and
• Hong Liu

Beilstein J. Org. Chem. 2014, 10, 2441–2447, doi:10.3762/bjoc.10.254

• Ullmann condensation is a powerful method for C–N coupling [24][25][26], especially the N-arylation of nitrogen-containing heterocycles such as indoles [27][28]. Indolo[1,2-a]quinazoline is a kind of tetracyclic compounds containing the indole motif that has been constructed by intramolecular [3 + 2

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• biologically significant nitrogen-containing heterocycles. To develop its asymmetric variant, Kwon and co-workers examined several common and commercially available chiral bisphosphines, as well as a series of newly prepared chiral aminophosphines [96]. Unfortunately, these phosphines displayed no or very poor

Microwave-assisted Cu(I)-catalyzed, three-component synthesis of 2-(4-((1-phenyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-1H-benzo[d]imidazoles

• Yogesh Kumar,
• Vijay Bahadur,
• Anil K. Singh,
• Virinder S. Parmar,
• Erik V. Van der Eycken and
• Brajendra K. Singh

Beilstein J. Org. Chem. 2014, 10, 1413–1420, doi:10.3762/bjoc.10.145

• : benzimidazole; Cu(I) catalysis; microwave-assisted synthesis; multicomponent; three component synthesis; Introduction Due to their structural range and biological importance nitrogen-containing heterocycles have been striking targets for many years. They are found in a variety of natural products and are

Synthesis of chiral N-phosphoryl aziridines through enantioselective aziridination of alkenes with phosphoryl azide via Co(II)-based metalloradical catalysis

• Jingran Tao,
• Li-Mei Jin and
• X. Peter Zhang

Beilstein J. Org. Chem. 2014, 10, 1282–1289, doi:10.3762/bjoc.10.129

• ; cobalt complex; metalloradical catalysis; organophosphorus; phosphoryl azide; Introduction Aziridines, the smallest three-membered nitrogen-containing heterocycles, are highly valuable heterocyclic compounds that are widely used in organic synthesis and pharmaceuticals [1][2]. As a result, tremendous

Atherton–Todd reaction: mechanism, scope and applications

• Stéphanie S. Le Corre,
• Mathieu Berchel,
• Hélène Couthon-Gourvès,
• Jean-Pierre Haelters and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

Four-component reaction of cyclic amines, 2-aminobenzothiazole, aromatic aldehydes and acetylenedicarboxylate

• Hong Gao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 2934–2939, doi:10.3762/bjoc.9.330

• : benzothiazole; domino reaction; electron-deficient alkyne; multicomponent reaction; pyrrolidinone; Introduction Over fifty years ago, Huisgen firstly described the addition reactions of nitrogen-containing heterocycles to electron-deficient alkynes to form 1,4-dipolar intermediates, which can reacted

• nitrogen-containing heterocycles [11][12][13][14][15][16]. In this hot research field, we also successfully developed a series of domino reactions containing primary amine, electron-deficient alkynes and the other components, and found several efficient synthetic protocols for versatile heterocycles and

New syntheses of 5,6- and 7,8-diaminoquinolines

• Maroš Bella and
• Viktor Milata

Beilstein J. Org. Chem. 2013, 9, 2669–2674, doi:10.3762/bjoc.9.302

• ; Introduction o-Diaminoquinolines, in particular 5,6- and 7,8-diaminoquinolines, represent valuable intermediates in the synthesis of nitrogen-containing heterocycles [1][2][3] including food-borne carcinogens [4]. To date, the known procedures for the synthesis of 7,8-diaminoquinoline have started from 3

Asymmetric Brønsted acid-catalyzed aza-Diels–Alder reaction of cyclic C-acylimines with cyclopentadiene

• Magnus Rueping and
• Sadiya Raja

Beilstein J. Org. Chem. 2012, 8, 1819–1824, doi:10.3762/bjoc.8.208

• with cyclopentadiene providing optically active nitrogen-containing heterocycles (Scheme 1). Results and Discussion Our initial study began with the examination of the the aza-Diels–Alder reaction of cyclic C-acylimine 1 with cyclopentadiene (2) in the presence of BINOL-derived phosphoric acid diesters

Organocatalytic cascade aza-Michael/hemiacetal reaction between disubstituted hydrazines and α,β-unsaturated aldehydes: Highly diastereo- and enantioselective synthesis of pyrazolidine derivatives

• Zhi-Cong Geng,
• Jian Chen,
• Ning Li,
• Xiao-Fei Huang,
• Yong Zhang,
• Ya-Wen Zhang and
• Xing-Wang Wang

Beilstein J. Org. Chem. 2012, 8, 1710–1720, doi:10.3762/bjoc.8.195

• 65880378 10.3762/bjoc.8.195 Abstract The catalytic synthesis of nitrogen-containing heterocycles is of great importance to medicinal and synthetic chemists, and also a challenge for modern chemical methodology. In this paper, we report the synthesis of pyrazolidine derivatives through a domino aza-Michael

Extending the utility of [Pd(NHC)(cinnamyl)Cl] precatalysts: Direct arylation of heterocycles

• Anthony R. Martin,
• Anthony Chartoire,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2012, 8, 1637–1643, doi:10.3762/bjoc.8.187

• investigated. Among four different precatalysts, [Pd(SIPr)(cinnamyl)Cl] proved to be the most efficient promoter of the reaction. The C–H functionalization of sulfur- or nitrogen-containing heterocycles has been achieved at low catalyst loadings. These catalyst charges range from 0.1 to 0.01 mol % palladium

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• sulfur dioxide. However, this Pd-catalyzed aminosulfonylation process proved inefficient with primary amines (Scheme 20) [20]. Multicomponent synthesis of nitrogen-containing heterocycles may also be initiated by an aza-Michael addition and terminated by a palladium-catalyzed ring-closure process [21

• developed several multicomponent approaches for the synthesis of nitrogen-containing heterocycles based on a palladium-mediated carbonylation reaction [44]. An interesting, related strategy for the preparation of unsaturated seven-membered ring lactams 84, starting from a Baylis–Hillman adduct bearing an

Continuous flow photolysis of aryl azides: Preparation of 3H-azepinones

• Farhan R. Bou-Hamdan,
• François Lévesque,
• Alexander G. O'Brien and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2011, 7, 1124–1129, doi:10.3762/bjoc.7.129

• water typically affords 3H-azepinone 7 [31][32][33][34], a moiety present in natural products [35][36] and in azepinone-derived pharmaceuticals [37][38]. Despite the importance of these 7-membered nitrogen-containing heterocycles, there remain few methods for their preparation [39][40][41][42][43][44