One-pot synthesis of diaryliodonium salts from arenes and aryl iodides with Oxone–sulfuric acid

• Natalia Soldatova,
• Pavel Postnikov,
• Olga Kukurina,
• Viktor V. Zhdankin,
• Akira Yoshimura,
• Thomas Wirth and
• Mekhman S. Yusubov

Beilstein J. Org. Chem. 2018, 14, 849–855, doi:10.3762/bjoc.14.70

• lower yield. With the optimized procedure, the synthetic utility of this method using various aryliodides and arenes was investigated (Table 2). Iodobenzene (1a) smoothly reacts with arenes containing electron-donating substituents to form the corresponding iodonium salts in high yields. 3

Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions

• Kendra Leahy Denlinger,
• Lianna Ortiz-Trankina,
• Preston Carr,
• Kingsley Benson,
• Daniel C. Waddell and
• James Mack

Beilstein J. Org. Chem. 2018, 14, 688–696, doi:10.3762/bjoc.14.57

• of the Wittig reaction under mechanochemical conditions [17][18]. The Wittig reaction is one of the most useful reactions for the synthesis of olefins [19][20][21][22][23]. Aside from its synthetic utility, its unique reaction mechanism (shown in Figure 1) and inherent diastereoselectivity has led to

Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

• Lingjun Xu,
• Shuwen Han,
• Linjie Yan,
• Haifeng Wang,
• Haihui Peng and
• Fener Chen

Beilstein J. Org. Chem. 2018, 14, 309–317, doi:10.3762/bjoc.14.19

• furnish the desired products. Application of this methodology to the synthesis of (S)-GABOB (13), a metabolic derivative of the neurotransmitter γ-aminobutanoic acid, was performed to illustrate the synthetic utility [58][59] (Scheme 2). From commercially available diethyl 3-hydroxyglutarate (10

Quinone-catalyzed oxidative deformylation: synthesis of imines from amino alcohols

• Xinyun Liu,
• Johnny H. Phan,
• Benjamin J. Haugeberg,
• Shrikant S. Londhe and
• Michael D. Clift

Beilstein J. Org. Chem. 2017, 13, 2895–2901, doi:10.3762/bjoc.13.282

• iminoquinone intermediate is likely required for productive reactivity. To demonstrate the synthetic utility of this methodology, we performed a sequential oxidative deformylation/Mukaiyama−Mannich addition under our previously reported conditions for decarboxylative amino acid homologation (Scheme 4) [32]. In

A Brønsted base-promoted diastereoselective dimerization of azlactones

• Danielle L. J. Pinheiro,
• Gabriel M. F. Batista,
• Pedro P. de Castro,
• Leonã S. Flores,
• Gustavo F. S. Andrade and
• Giovanni W. Amarante

Beilstein J. Org. Chem. 2017, 13, 2663–2670, doi:10.3762/bjoc.13.264

• reaction order for azlactone has also been confirmed using the technique of initial rates varying the initial concentrations of azlactone 1a (See Supporting Information File 1). Finally, the synthetic utility of the dimerization products was demonstrated by stereocontrolled reduction of the dimer 2c

Enzymatic separation of epimeric 4-C-hydroxymethylated furanosugars: Synthesis of bicyclic nucleosides

• Neha Rana,
• Manish Kumar,
• Vinod Khatri,
• Jyotirmoy Maity and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2017, 13, 2078–2086, doi:10.3762/bjoc.13.205

• acetylation, has been confirmed by an X-ray study on their corresponding 4-C-p-toluenesulfonyloxymethyl derivatives. Furthermore, the two separated epimers were used for the convergent synthesis of two different types of bicyclic nucleosides, which confirms their synthetic utility. Keywords

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives

• Roman A. Irgashev,
• Nikita A. Kazin,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2017, 13, 1396–1406, doi:10.3762/bjoc.13.136

• reductive conditions, forming 6,12-unsubstituted derivatives as major products. At the same time, 6,12-dinitro-ICZs demonstrate a remarkable synthetic utility, since both electrophilic and nucleophilic aromatic substitution procedures can successfully be used for their transformations. For instance, we have

Studies directed toward the exploitation of vicinal diols in the synthesis of (+)-nebivolol intermediates

• Runjun Devi and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2017, 13, 571–578, doi:10.3762/bjoc.13.56

• heterocycles has been tremendous, its synthetic utility toward chiral benzo-annulated heterocycles is relatively limited. Thus, in the search for wider applications of Sharpless asymmetric dihydroxylation-derived diols for the synthesis of benzo-annulated heterocycles, we report herein our studies in the

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

• Ramana Sreenivasa Rao and
• Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

• evidence for cyclized compounds 9b and 10a was supported by single-crystal X-ray diffraction analysis (Figure 3) in addition to IR, NMR and HRMS data. To show the synthetic utility of substituted pyrazinones, we introduce a phenyl group at the C-3 position in pyrazinone derivative 10a. To begin with, the

• -diamides furnished the substituted pyrazinones through an acid–mediated dehydrosulfonylation in methanol. This strategy can be adopted to develop value added pyrazinone-based potential precursors useful to synthesize various drug targets. Further, the synthetic utility of pyrazinoisoquinoline was

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

• Anna Zaghi,
• Daniele Ragno,
• Graziano Di Carmine,
• Carmela De Risi,
• Olga Bortolini,
• Pier Paolo Giovannini,
• Giancarlo Fantin and
• Alessandro Massi

Beilstein J. Org. Chem. 2016, 12, 2719–2730, doi:10.3762/bjoc.12.268

• examples, α-hydroxy ketones (benzoin reaction) and 1,4-diketones (Stetter reaction) [1][2][3][4]. The synthetic utility of the umpolung methodology has therefore spurred intensive research on process intensification through the heterogeneization of NHC catalysts [5][6][7][8][9] for facilitating the post

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• . The synthetic utility of pyEDOT is demonstrated by the following examples involving a range of pendant groups. The electron acceptor units diethyl terephthalate (DET) and 9,10-anthraquinone (AQ) are of particular interest for their redox chemistry in energy storage applications [34]. Their ester and

Development of a continuous process for α-thio-β-chloroacrylamide synthesis with enhanced control of a cascade transformation

• Olga C. Dennehy,
• Valérie M. Y. Cacheux,
• Benjamin J. Deadman,
• Denis Lynch,
• Stuart G. Collins,
• Humphrey A. Moynihan and
• Anita R. Maguire

Beilstein J. Org. Chem. 2016, 12, 2511–2522, doi:10.3762/bjoc.12.246

• -chloroacrylamides; cascade reactions; flow chemistry; Introduction Since the efficient and highly stereoselective transformation of α-thioamides to the corresponding α-thio-β-chloroacrylamides derivatives was first reported [1][2], the considerable synthetic utility of these heavily functionalized acrylamide

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

• macrocyclisation found in NRP biosynthesis, although the energetic demands of breaking an amide bond versus a thioester bond are notably different. PatG may have synthetic utility, as studies with unnatural substrates have shown that macrocycles of between 5–22 residues can be produced [108], despite it naturally

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• article, we disclose the scope and limitations of 'transition-metal-free' IDC of Csp2-H and Csp3-H using iodine and N-iodosuccinimide (NIS) as oxidants. In addition, we have also demonstrated the synthetic utility of oxidative coupling products in the syntheses of 3-substituted-2-oxindoles, via a

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• . Inspired by the biological potential and synthetic utility, metal- or organo-catalyzed asymmetric synthesis of chiral 3-hydroxyoxindoles have been highly pursued in the last decades. An excellent review by Chimni and co-workers summarized the catalytic strategies for the enantioselective synthesis of

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• (>95:5 dr and up to 96% ee), employing only 3 mol % catalyst loading. The synthetic utility of the process was further expanded by the multigram version of the reaction utilizing only 0.5 mol % catalyst loading and by the transformations of the adducts into other synthetic intermediates by oxidation

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

• Ping Qian,
• Bingnan Du,
• Wei Jiao,
• Haibo Mei,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32

• corresponding products (5ae1–5ae5) with 42% total yield. To extend the synthetic utility of this radical cyclization reaction, N-methacryloyl-N-methylbenzamide derivatives 6 were then tried as substrates for this reaction (Scheme 4). It should be mentioned that only a few radical precursors, such as the TMSCF3

Direct estimate of the internal π-donation to the carbene centre within N-heterocyclic carbenes and related molecules

• Diego M. Andrada,
• Nicole Holzmann,
• Thomas Hamadi and
• Gernot Frenking

Beilstein J. Org. Chem. 2015, 11, 2727–2736, doi:10.3762/bjoc.11.294

• has become a major field of chemical research [2][3][4]. The outstanding stability and synthetic utility of N-heterocyclic carbenes (NHCs) is an ongoing subject to an ubiquitous number of experimental and computational studies exploring their structural and electronic properties [5][6][7][8]. In the

Enantioselective additions of copper acetylides to cyclic iminium and oxocarbenium ions

• Jixin Liu,
• Srimoyee Dasgupta and
• Mary P. Watson

Beilstein J. Org. Chem. 2015, 11, 2696–2706, doi:10.3762/bjoc.11.290

• , alkyl, and trimethylsilyl substituents result in 90–98% ee. The synthetic utility of these products, as well as their absolute configuration, was demonstrated by their reduction to the natural products (+)-galipinine, (+)-cuspareine, and (−)-angustureine. Additions to oxocarbenium ions Similar to the

Chiral Cu(II)-catalyzed enantioselective β-borylation of α,β-unsaturated nitriles in water

• Lei Zhu,
• Taku Kitanosono,
• Pengyu Xu and
• Shū Kobayashi

Beilstein J. Org. Chem. 2015, 11, 2007–2011, doi:10.3762/bjoc.11.217

• reactions, which exhibit extremely high TOF values, can be performed easily without requiring the preparation of an array of chiral ligands [1][16][17][18][19]. Rapid protonation in water subsequent to β-borylation would liberate the desired adducts almost instantaneously. In addition to the synthetic

• utility of enantiomerically enriched β-boryl nitriles, Cu(II)-based activation of α,β-unsaturated nitriles in water is mechanistically curious. In previous reports, homogeneous catalysts composed of Cu(OAc)2 were found to be more effective than insoluble Cu(OH)2-based catalysts in the asymmetric β

Synthesis of quinoline-3-carboxylates by a Rh(II)-catalyzed cyclopropanation-ring expansion reaction of indoles with halodiazoacetates

• Magnus Mortén,
• Martin Hennum and
• Tore Bonge-Hansen

Beilstein J. Org. Chem. 2015, 11, 1944–1949, doi:10.3762/bjoc.11.210

• three reactions and the yields were 90% (X = Cl), 84% (X = Br) and 70% (X = I). The synthetic utility of the heterocyclic cyclopropanation-ring expansion reaction has been limited due to very low yields, strong basic reaction conditions, high temperature and formation of large amounts of polymeric

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF₅-substituted phenylboronic esters and iodobenzenes

• George Iakobson,
• Junyi Du,
• Alexandra M. Z. Slawin and
• Petr Beier

Beilstein J. Org. Chem. 2015, 11, 1494–1502, doi:10.3762/bjoc.11.162

• [68] applied to 3b provided 8b in only 25% 19F NMR yield. To extend the synthetic utility of the pyridine-mediated derivatization of aryldiazonium tetrafluoroborates we investigated the reaction with iodobenzene and iodine as efficient scavengers of aryl radicals [83][84]. A competitive experiment

Development of variously functionalized nitrile oxides

• Haruyasu Asahara,
• Keita Arikiyo and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2015, 11, 1241–1245, doi:10.3762/bjoc.11.138

• -methylcarbamoyl functional group. The synthetic utility of nitrile oxide 2 will be indeed improved by converting the N-methylcarbamoyl group into other functionalities, i.e., nitrile oxide 2 may serve as an equivalent of nitrile oxides 4 having versatile functional groups (Scheme 1). Weinreb amide (N-methoxy-N

• activation of the carbamoyl group and for preventing over-addition by organometallic reagents. Isoxazole-3-carboxamide 3 was successfully converted in a similar fashion. Thus, as shown in Figure 1, nitrile oxide 2 serves as an equivalent of functionalized nitrile oxides 4, thereby improving the synthetic

• utility of carbamoylnitrile oxide 2. Experimental Conversion of isoxazolecarboxamide 3 to 5c via tosyl derivative 12 To a solution of amide 3 (101 mg, 0.5 mmol) in THF (1 mL), a suspension of 60 wt % sodium hydride (100 mg, 2.5 mmol) in THF (3 mL) was added under argon. After the mixture was stirred

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• immobilization of imidazolidin-4-one onto hyperbranched polyglycerol (hPG) and its application as multivalent organocatalyst. Results and Discussion To explore the synthetic utility of hPG in organocatalysis, we here report the synthesis and application of a series of three multivalent dendronized imidazolidin-4