Fluorohydration of alkynes via I(I)/I(III) catalysis

• Jessica Neufeld,
• Constantin G. Daniliuc and
• Ryan Gilmour

Beilstein J. Org. Chem. 2020, 16, 1627–1635, doi:10.3762/bjoc.16.135

• these species in inhibiting aconitase [22] must be reconciled with synthetic utility. To that end, catalysis-based strategies to unmask the venerable α-fluorocarbonyl motif [23] from a terminal alkyne were considered (Figure 1). This general strategy was appealing given the commercial availability of

Azidophosphonium salt-directed chemoselective synthesis of (E)/(Z)-cinnamyl-1H-triazoles and regiospecific access to bromomethylcoumarins from Morita–Baylis–Hillman adducts

• Soundararajan Karthikeyan,
• Radha Krishnan Shobana,
• Kamarajapurathu Raju Subimol,
• J. Helen Ratna Monica and
• Ayyanoth Karthik Krishna Kumar

Beilstein J. Org. Chem. 2020, 16, 1579–1587, doi:10.3762/bjoc.16.130

• ) acetylation, (ii) azidation, and (iii) cycloaddition to produce IV–VIII. In spite of the broad scope and synthetic utility, it is evident that the multistep synthetic methodology is the only existing module for cycloaddition reactions. Our research group is focused on developing one-pot synthetic

• transformations employed quaternary phosphonium salts as favourable catalysts [36]. Their synthetic utility was not only confined to catalysis, but they were also used as intermediates for the synthesis of 1H-indazoles [37], as promoters for stereoselective rearrangements [38], and as temporary protectors of O,P

• ). The synthetic utility of the reaction was further extended to ortho-vanillin and para-bromobenzaldehyde to afford the corresponding halomethylcoumarins (4b/c). However, this regiospecific transformation was restricted only to the MBH adducts derived from salicyladehydes and tert-butyl acrylate [52][53

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• that the PhSO2CF2Cu species might be prepared from difluoromethylphenylsulfone (PhSO2CF2H) and used it to functionalize an array of (hetero)aromatic boronic acids [62] (Scheme 12). The transformation showed a good functional group tolerance (aldehyde, CN, halogens). Note that the synthetic utility of

• different approaches developed to synthesize CF2CH3-containing molecules, Wang, Hu and co-workers demonstrated the possibility to use 1,1-difluoroethylsilane (TMSCF2CH3) as a precursor for the in situ generation of the corresponding CuCF2CH3 species [64]. The synthetic utility of this copper-based reagent

• either from the pre-isolated (K(DMF))Cu(Ot-Bu)2 or in situ from CuCl, t-BuOK in DMF in a nearly quantitative yield. The copper reagent was used for the pentafluoroethylation of a panel of (hetero)aryl iodides and bromides (up to 99% 19F NMR yield) and its synthetic utility was further demonstrated with

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

• Liliia Moshniaha,
• Marika Żyła-Karwowska,
• Joanna Cybińska,
• Piotr J. Chmielewski,
• Ludovic Favereau and
• Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

• ], with FeCl3 being particularly notable for its versatility, ease of use, and low price [5]. Nevertheless, the synthetic utility of oxidative couplings is often limited by several factors [6]. Consequently, incomplete ring fusion and various side reactions, e.g., chlorination [7], or unexpected

Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin

• Anna R. Bockman and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2020, 16, 509–514, doi:10.3762/bjoc.16.46

• Anna R. Bockman Jeffrey M. Pruet Department of Chemistry, Valparaiso University, 1710 Chapel Dr, Valparaiso, IN 46383, USA 10.3762/bjoc.16.46 Abstract The synthetic utility of pterins is often hampered by the notorious insolubility of this heterocycle, slowing the development of medicinally

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• [Cu(I)(dap)2]Cl under green light irradiation (Scheme 5) [21]. Fluorinated sultones are important scaffolds for pharmaceutical syntheses. To illustrate the synthetic utility of the method, a novel benzoxathiin analog was synthesized using this reaction as the key step. The authors suggested a similar

• , acrylates, enol acetates, and enamines. The functional group tolerance of the transformation was fairly decent and demonstrated the synthetic utility of this reaction manifold. To explain the reaction outcome, the authors suggested the following mechanism: The excited copper catalyst reduces the CF3SO2Cl

• moderate to good yields. Notably, alkyl iodides were also suitable substrates. The methodology proved to be compatible with a broad range of functional groups. To demonstrate the synthetic utility of the process, the reaction was developed under continuous flow conditions to afford an easy and

Combination of multicomponent KA² and Pauson–Khand reactions: short synthesis of spirocyclic pyrrolocyclopentenones

• Riccardo Innocenti,
• Elena Lenci,
• Gloria Menchi and
• Andrea Trabocchi

Beilstein J. Org. Chem. 2020, 16, 200–211, doi:10.3762/bjoc.16.23

• Pauson–Khand conditions (Table 1,entry 14). The synthetic utility of the spiro derivatives resulting from the combined KA2/Pauson–Khand process to generate second-generation molecular scaffolds was tested on compound 5 by applying representative reactions on the enone structural motif (Scheme 3). The

Regioselective addition of Grignard reagents to N-acylpyrazinium salts: synthesis of substituted 1,2-dihydropyrazines and Δ⁵-2-oxopiperazines

• Valentine R. St. Hilaire,
• William E. Hopkins,
• Yenteeo S. Miller,
• Srinivasa R. Dandepally and
• Alfred L. Williams

Beilstein J. Org. Chem. 2019, 15, 72–78, doi:10.3762/bjoc.15.8

• adding to 2-cyano-6-morpholinylpyrazine [21]. As a part of our continued exploration into the synthetic utility of N-acylpyrazinium salts, herein we report the regioselective addition of Grignard reagents to mono- and disubstituted N-acylpyrazinium salts towards the synthesis of 1,2-dihydropyrazines and

• -oxopiperazines. These compounds can potentially serve as templates for making substituted 2-oxopiperazines. The investigation into the synthetic utility of this reaction is currently underway and will be reported in due course. Regioselective addition of Grignard reagents to mono- and disubstituted pyrazinium

The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX

• Md Toufique Alam,
• Saikat Maiti and
• Prasenjit Mal

Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216

• aniline derivative with moderate reactivity. Therefore, we anticipate that the controlled reactivity of IBX under mechano-milling conditions led to successful reaction with 2-aminobenzamide. Finally, a large scale synthesis was performed to prove the synthetic utility of this methodology. By taking

Hypervalent iodine compounds for anti-Markovnikov-type iodo-oxyimidation of vinylarenes

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Mikhail A. Syroeshkin,
• Alexander A. Korlyukov,
• Pavel V. Dorovatovskii,
• Yan V. Zubavichus,
• Gennady I. Nikishin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2018, 14, 2146–2155, doi:10.3762/bjoc.14.188

• %) without column chromatography (Scheme 4). The synthetic utility of the obtained products 3aa and 3ab was demonstrated by the substitution of the iodine atom with O- (methanol), S- (benzenesulfinate) and N- (azide) nucleophiles (Scheme 5). It is noteworthy that the reaction of compound 3aa with sodium

• –ka, 3ab–db, 3fb, 3hb, and 3kb. The proposed mechanism of iodo-oxyimidation of styrene (1a) using the NHPI/I2/PhI(OAc)2 system with the formation of product 3aa. Gram-scale synthesis of compound 3aa. Synthetic utility of the iodo-oxyimides 3aa and 3ab. Optimization of the synthesis of iodo

Thiocarbonyl-enabled ferrocene C–H nitrogenation by cobalt(III) catalysis: thermal and mechanochemical

• Santhivardhana Reddy Yetra,
• Zhigao Shen,
• Hui Wang and
• Lutz Ackermann

Beilstein J. Org. Chem. 2018, 14, 1546–1553, doi:10.3762/bjoc.14.131

• products, the amidated thiocarbonylferrocene 3aa could be easily transformed into the corresponding synthetically useful aminoketone 4aa (Scheme 6), illustrating the unique synthetic utility of our strategy. Mechanochemical molecular synthesis has attracted recent renewed attention as an attractive

Synthesis of chiral 3-substituted 3-amino-2-oxindoles through enantioselective catalytic nucleophilic additions to isatin imines

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 1349–1369, doi:10.3762/bjoc.14.114

• enantioselectivities (90–94% ee), as shown in Scheme 5. The synthetic utility of this novel methodology was demonstrated through the total synthesis of the natural product (−)-psychotriasine (Scheme 5) and the biologically active compound AG-041R (Scheme 1). By using another type of organocatalyst, such as L

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• ]. Here, symmetrical diaryliodonium salts 1 were used in a palladium-catalysed cross-coupling reaction with sodium tetraphenylborate (Scheme 3). This reaction not only provides excellent yields of the respective biphenyls 3 but also exhibits a high AE (57% for Ar = Ph). However, its general synthetic

• utility is limited since it requires highly reactive boron compounds as nucleophiles. Symmetrical biphenyls 3’ can be generated from the corresponding symmetrically substituted diaryliodonium salts 1 and bis(pinacolato)diboron as demonstrated by Muñiz and co-workers [25]. In the first step, a mild carbon

Recyclable hypervalent-iodine-mediated solid-phase peptide synthesis and cyclic peptide synthesis

• Dan Liu,
• Ya-Li Guo,
• Jin Qu and
• Chi Zhang

Beilstein J. Org. Chem. 2018, 14, 1112–1119, doi:10.3762/bjoc.14.97

• [43][44]. Due to the particular significance of cyclic peptides, chemists pay considerable attention to the efficient synthesis of cyclic peptides [45]. In the second part of the investigation of the synthetic utility of the FPID/(4-MeOC6H4)3P system, we tested this system in the cyclic peptide

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