Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

• Ken Tamamoto,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

• ), demonstrating a promising pathway for constructing CF2CF2-containing heterocyclic compounds. We also demonstrated the multigram preparation of CF2CF2-containing arenes through the present cross-coupling reaction, as shown in Scheme 2. Thus, treatment of 1.38 g (5.00 mmol) of ethyl o-iodobenzoate (3j) with 10.1

Chiral bisoxazoline ligands designed to stabilize bimetallic complexes

• Deepankar Das,
• Rudrajit Mal,
• Nisha Mittal,
• Zhengbo Zhu,
• Thomas J. Emge and
• Daniel Seidel

Beilstein J. Org. Chem. 2018, 14, 2002–2011, doi:10.3762/bjoc.14.175

• Deepankar Das Rudrajit Mal Nisha Mittal Zhengbo Zhu Thomas J. Emge Daniel Seidel Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3⁺ + 2]-cycloaddition/rearrangement reactions

• Lin-bo Luan,
• Zi-jie Song,
• Zhi-ming Li and
• Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

• furnishing the tricyclic 1,2,4-triazole-fused 1,4-benzodiazepines. Keywords: 1,4-benzodiazepine (BDZ); cyclization; hydrazones; oxidation; rearrangement; Introduction Heterocyclic compounds comprising a 1,4-benzodiazepine (BDZ) ring have been a topic of continued interest as they exhibit a wide spectrum of

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• that resorcinarenes are particularly suited hosts for both neutral and protonated N-heterocyclic compounds [19][20] and alkyl ammonium cations [21][22][23][24][25]. The resulting complexes have been extensively studied in both solid and solution state. The most common defined interactions involve

An air-stable bisboron complex: a practical bidentate Lewis acid catalyst

• Longcheng Hong,
• Sebastian Ahles,
• Andreas H. Heindl,
• Gastelle Tiétcha,
• Andrey Petrov,
• Zhenpin Lu,
• Christian Logemann and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 618–625, doi:10.3762/bjoc.14.48

• of cyclic frameworks, especially in the synthesis of natural products [1][2]. Aza-dienes have been utilized in IEDDA reactions for the construction of nitrogen-containing heterocyclic compounds [3][4][5][6][7][8]. Among them, 1,2-diazines are less used owing to their relative low reactivity as their

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• intermediate reacts with the nucleophile (dienophile) species in different reactions to form a wide range of heterocyclic compounds. Reactions with C=C dienophiles Reactions of o-QMs with different C=C dienophiles are listed in Table 3. Osyanin et al. reported the efficient reaction of quaternary ammonium salt

Synthesis of fluoro-functionalized diaryl-λ³-iodonium salts and their cytotoxicity against human lymphoma U937 cells

• Prajwalita Das,
• Etsuko Tokunaga,
• Hidehiko Akiyama,
• Hiroki Doi,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

• could themselves be highly potential drug candidates. All of the reagents that we developed contain at least one fluorine atom in their structures, which may explain why they have potential biological activity [4][5][6][7][8][9]. In addition, examination of the successful records of heterocyclic

• compounds in the pharmaceutical history indicates that some of these reagents have a heterocyclic skeleton which makes them suitable as drug candidates [29][30][31][32]. Among these compounds, our group is interested in investigating the biological activity of hypervalent iodine-type reagents [33

One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na₂S₂O₈

• Teppei Sasaki,
• Katsuhiko Moriyama and
• Hideo Togo

Beilstein J. Org. Chem. 2018, 14, 345–353, doi:10.3762/bjoc.14.22

• transformed into 4-phenylcoumarin derivatives bearing C–H, C–S, C–N, and C–C bonds at 3-position. Keywords: 3-aryl-2-propynoic acid; bromo-cyclization; coumarin; diaryliodonium triflate; O-phenylation; Introduction Coumarin is a benzo-α-pyrone and one of the typical heterocyclic compounds. The importance of

• the preparation of heterocyclic compounds [43][44][45][46], we would like to report an efficient one-pot preparation of 4-aryl-3-bromocoumarins by treatment of 3-aryl-2-propynoic acids with diaryliodonium triflate in the presence of a base, followed by the reaction with tetrabutylammonium bromide

Continuous-flow retro-Diels–Alder reaction: an efficient method for the preparation of pyrimidinone derivatives

• Imane Nekkaa,
• Márta Palkó,
• István M. Mándity and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2018, 14, 318–324, doi:10.3762/bjoc.14.20

• ] syntheses of heterocyclic compounds. The rDA products can be gained, due to a thermal [4 + 2]-cycloreversion, by distillation under reduced pressure [29], boiling in solvent [30][31], and applying microwave irradiation [32][33][34][35] or flash vacuum pyrolysis [35][36]. rDA reactions under mild conditions

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

• Anna Kuźnik,
• Roman Mazurkiewicz and
• Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

• yield of 10–36% [41]. 2.2. Vinylphosphonium salts in the intramolecular Wittig reaction As was already mentioned, in 1964 Schweizer provided a general method for preparing carbo- and heterocyclic compounds 38 using vinylphosphonium salts [1][2]. The method consisted in the reaction of oxygen, nitrogen

• provided two final four- and five-membered reaction products 94 and 95, respectively (Scheme 56) [69]. Another example of the generation of heterocyclic compounds via the intramolecular Wittig reaction is the synthesis of quinoline derivatives 99 from triphenylphosphine, acetylenedicarboxylic acid esters

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

• Sergii V. Melnykov,
• Andrii S. Pataman,
• Yurii V. Dmytriv,
• Svitlana V. Shishkina,
• Mykhailo V. Vovk and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

• -containing heterocyclic compounds [24][25][26][27][28][29]. It should be noted that the presence of a strong electron-withdrawing trifluoromethyl group is responsible for the sufficient reactivity of the electrophilic ketimine function with various carbon nucleophiles in these reactions. Recently, the

A novel synthetic approach to hydroimidazo[1,5-b]pyridazines by the recyclization of itaconimides and HPLC–HRMS monitoring of the reaction pathway

• Dmitry Yu. Vandyshev,
• Khidmet S. Shikhaliev,
• Andrey Yu. Potapov,
• Michael Yu. Krysin,
• Fedor I. Zubkov and
• Lyudmila V. Sapronova

Beilstein J. Org. Chem. 2017, 13, 2561–2568, doi:10.3762/bjoc.13.252

• virtually any carbon atom of the heterocyclic system is achievable in addition to hydrogenated imidazo[1,5-b]pyridazines [34][35]. Itaconimides, in contrast to itaconic acid, its esters, monoamides or anhydride [36][37], scarcely have been studied in the synthesis of heterocyclic compounds. The presence of

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

• membranes. The conjugation of adamantane with heterocyclic compounds also provides a method to modify the pharmacological profile and frequently leads to a new type of bioactivity. For example, N-adamantyl tetrazoles 1 and 2 (Figure 1A) demonstrate lower toxicity and, simultaneously, more potent activity

• the studies of N-alkylated heterocyclic compounds with a high abundance of nitrogen nuclei, where 13C chemical shifts and 1H-1H NOE data cannot provide reliable structural information. The incorporation of the 15N-labels also permitted the study of the mechanism of isomerization of N-adamantylated

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

• Yaroslav D. Boyko,
• Valentin S. Dorokhov,
• Alexey Yu. Sukhorukov and
• Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

• unreactive under these conditions. Electron-rich aromatic heterocyclic compounds such as pyrroles and indoles enter reactions with nitrosoalkenes more smoothly [44][45][46][47][48][49][50][51][52][53][54][55]). The addition of nitrosoalkenes to pyrroles and indoles is a convenient and mild strategy for the

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• acid is readily achieved by adding 2 N NaOH/water solution to the silylated phosphonate [178]. This two-step sequence: 1. bromotrimethylsilane; 2. methanolysis or hydrolysis was used for the synthesis of numerus phosphonic acids including heterocyclic compounds that are too sensitive to be prepared by

Preparation of imidazo[1,2-a]-N-heterocyclic derivatives with gem-difluorinated side chains

• Layal Hariss,
• Kamal Bou Hadir,
• Mirvat El-Masri,
• Thierry Roisnel,
• René Grée and
• Ali Hachem

Beilstein J. Org. Chem. 2017, 13, 2115–2121, doi:10.3762/bjoc.13.208

• coupling reactions as well as nucleophilic substitutions have been performed successfully in order to increase the molecular diversity. Keywords: aerobic oxidative coupling; imidazo[1,2-a]-N-heterocycles; gem-difluoroalkyl derivatives; propargylic fluorides; Introduction Nitrogen-containing heterocyclic

• compounds are frequently found in bioactive naturally occurring compounds, as well as in the synthetic pharmacopeia. Imidazo[1,2-a]pyridine is an important heterocyclic system present in many molecules featuring diverse biological activities, such as antiviral, antimicrobial, antitumor, anti-inflammatory

Metal-free hydroarylation of the side chain carbon–carbon double bond of 5-(2-arylethenyl)-3-aryl-1,2,4-oxadiazoles in triflic acid

• Anna S. Zalivatskaya,
• Dmitry S. Ryabukhin,
• Marina V. Tarasenko,
• Alexander Yu. Ivanov,
• Irina A. Boyarskaya,
• Elena V. Grinenko,
• Ludmila V. Osetrova,
• Eugeniy R. Kofanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2017, 13, 883–894, doi:10.3762/bjoc.13.89

• , N4,C-diprotonated forms of oxadiazoles are the electrophilic intermediates in this reaction. Keywords: Friedel–Crafts reaction; hydroarylation; oxadiazoles; superelectrophilic activation; triflic acid; Introduction Oxadiazoles are an important class of heterocyclic compounds and great attention has

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

• Gabriel P. Costa,
• Natália Seus,
• Juliano A. Roehrs,
• Raquel G. Jacob,
• Ricardo F. Schumacher,
• Thiago Barcellos,
• Rafael Luque and
• Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

• ; organocatalysis; organoselenium compounds; sonochemistry; 1,2,3-triazoles; Introduction Substituted 1,2,3-triazoles are an interesting class of heterocyclic compounds distinguished by their biological activities [1][2][3] as well as in various fields of chemistry [4][5][6][7][8][9][10][11][12][13][14][15]. The

Isoxazole derivatives as new nitric oxide elicitors in plants

• Anca Oancea,
• Emilian Georgescu,
• Florentina Georgescu,
• Alina Nicolescu,
• Elena Iulia Oprita,
• Catalina Tudora,
• Lucian Vladulescu,
• Marius-Constantin Vladulescu,
• Florin Oancea and
• Calin Deleanu

Beilstein J. Org. Chem. 2017, 13, 659–664, doi:10.3762/bjoc.13.65

• ; Introduction Isoxazoles are an interesting class of N-heterocyclic compounds intensely studied mainly due to their wide range of biological activity [1][2]. Isoxazole compounds show antiviral [3][4], antithrombotic [5][6][7][8][9], analgesic [9], COX-2 inhibitory [10][11], anti-inflamatory [9][11

• known as reactive 1,3-dipoles involved in 1,3-dipolar cycloaddition reactions with various dipolarophiles generating five-membered heterocyclic compounds, such as isoxazoles, isoxazolines, oxadiazoles, oxadiazolines, dioxazolidines etc. [23][24][25]. Intermediate nitrile oxides are usually generated in

• procedures towards isoxazole derivatives were developed [36][37]. As part of our continued efforts to develop simple synthetic routes towards bioactive heterocyclic compounds [38][39][40][41][42][43], we report here the synthesis of several 3,5-isoxazole derivatives, bearing benzo[1,3]dioxole and thiophene

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

• bonds was estimated to be −16.8 kcal/mol whereas the corresponding binding energy for the H2O/Cl− complex was determined to be −15.4 kcal/mol. Electron-deficient heterocyclic compounds such as 1,2,3-triazoles may also serve as strong C–H hydrogen bond donors. Substituted 1,2,3-triazoles possess a

cis-Diastereoselective synthesis of chroman-fused tetralins as B-ring-modified analogues of brazilin

• Dimpee Gogoi,
• Runjun Devi,
• Pallab Pahari,
• Bipul Sarma and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2016, 12, 2816–2822, doi:10.3762/bjoc.12.280

• the synthesis of carbo- and heterocyclic compounds [21][22][23][24]. The easy accessibility of racemic and enantiomerically pure epoxy substrates through a number of well-established epoxidation methods coupled with procedural simplicity, high atom economy, regio- and stereoselectivity of IFCEA

Synthesis of spiro[isoindole-1,5’-isoxazolidin]-3(2H)-ones as potential inhibitors of the MDM2-p53 interaction

• Salvatore V. Giofrè,
• Santa Cirmi,
• Raffaella Mancuso,
• Francesco Nicolò,
• Giuseppe Lanza,
• Laura Legnani,
• Agata Campisi,
• Maria A. Chiacchio,
• Michele Navarra,
• Bartolo Gabriele and
• Roberto Romeo

Beilstein J. Org. Chem. 2016, 12, 2793–2807, doi:10.3762/bjoc.12.278

• -dipolar cycloaddition process have been rationalized through a mechanistic study on the basis of our expertise in the study of cycloaddition reactions and heterocyclic compounds [37][38][39][40][41][42]. Calculations were performed using the Gaussian09 program package, [43] through optimizations with the

Catalytic Wittig and aza-Wittig reactions

• Zhiqi Lao and
• Patrick H. Toy

Beilstein J. Org. Chem. 2016, 12, 2577–2587, doi:10.3762/bjoc.12.253

• by Marsden (Scheme 14). In their report they also described the synthesis of various other classes of heterocyclic compounds such as 3H-1,4-benzodiazepin-2(1H)-ones 65, 3H-1,4-benzodiazepin-5(4H)-ones 66, and pyrrole 67 from the corresponding starting materials using similar reaction conditions. In

• reduced using diphenylsilane. It is readily evident from the above examples that regardless of whether phosphine or phosphine oxides were used as the catalyst, catalytic aza-Wittig reactions have emerged to become powerful tools in the synthesis of collections of various heterocyclic compounds since it

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

• have been the subject of various reviews [6][7][8][9][10][11][12][13][14][15]. Sydnones 3 are mesoionic heterocyclic compounds with a 1,2,3-oxadiazole skeleton and their chemistry and biological properties are well represented and documented in the literature [20][21][22][23][24][25][26]. The most

Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• this case, the primary alkylation adducts might be unstable and undergo heterocyclization reactions (on the synthesis of heterocyclic compounds from azoalkenes and diamines see [54][55][56]). Bishydrazones containing clickable groups (like 3) can be introduced into functional molecules or immobilized