Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• fluorescent 5-(dimethylamino)-N-(prop-2-yn-1-yl)naphthalene-1-sulfonamide (synthesized according to [18]) using CuI and TBTA [19] catalysis. All of the synthesized compounds were thoroughly described by NMR (Supporting Information File 1, Table S1), IR, optical rotation (Supporting Information File 1, section

• . Synthesis of 11-(5-(4-((5-(dimethylamino)naphthalene-1-sulfonamido)methyl)-1H-1,2,3-triazol-1-yl)pentanoylarchangelolide (5) To a solution of azidovalerate 4 (40 mg, 0.063 mmol) and 5-(dimethylamino)-N-(prop-2-yn-1-yl)naphthalene-1-sulfonamide (20 mg, 0.07 mmol) in THF (3 mL), CuI (50 µL of 1 M water

Robust perfluorophenylboronic acid-catalyzed stereoselective synthesis of 2,3-unsaturated O-, C-, N- and S-linked glycosides

• Madhu Babu Tatina,
• Xia Mengxin,
• Rao Peilin and
• Zaher M. A. Judeh

Beilstein J. Org. Chem. 2019, 15, 1275–1280, doi:10.3762/bjoc.15.125

• and trimethyl(propargyl)silane), S-nucleophiles (using thiophenol and p-toluenethiol) and N-nucleophiles (methane sulfonamide and p-toluene sulfonamide) (Figure 1). In all the cases, the reactions successfully gave the respective 2,3-unsaturated glycosides 3a–u in up to 92% yield with mainly α

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• mimetics More recently, Ji et al. published two classes of sulfonyladenosine inhibitors, more precisely the sulfamate/sulfamide inhibitors 5–9 and the vinyl sulfonamide inhibitors 10 and 11 (Figure 5). While the latter showed very low affinity for the protein, the former displayed Ki values between 88 nM

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• , Titz et al. have developed small molecule LecB inhibitors derived from mannose and obtained potent monovalent inhibitors (compound 15) of LecB-mediated bacterial adhesion [47]. The sulfonamide 15 and cinnamide 16 were developed to take advantage of interactions with a nearby shallow pocket, and indeed

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• . Considering that Ered*(cat/cat•−) is greater than +2 V (vs SCE) for acridinium salts, the limited oxidising power is not the most probable explanation. Instability of the heteroaromatic radical cation seems more plausible. The authors explore both aromatic and heteroaromatic pendant groups on the sulfonamide

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

• Xiang Li,
• Pinhong Chen and
• Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

• of substrates bearing either two or four methylene groups between the alkene and sulfonamide failed to provide the fluoroheterocycles. Difluorination of alkenes Hara and co-workers reported a vicinal difluorination of unactivated alkenes in the presence of stoichiometric amounts of difluoro

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• systems. In 2015, Jain and Ciufolini [124] developed PIDA-mediated spirocyclization of 2-naphtholic sulfonamides 124 to spiropyrrolidine derivatives 125. The spirocyclization reactions were carried out by treating N-sulfonamide substrates 124 with (diacetoxyiodo)benzene (15) in trifluoroacetic acid (TFA

• electrophile. PIDA-mediated spirocyclization of phenolic sulfonamide 122 to spiroketones 123. Iodine(III)-mediated oxidative spirocyclization of 2-naphthol derivatives 124 to spiropyrrolidines 125. PIDA-mediated oxidative spirocyclization of m-substituted phenols 126 to tricyclic spiroketals 127. Iodine(III

Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

• Eric Detmar,
• Valentin Müller,
• Daniel Zell,
• Lutz Ackermann and
• Martin Breugst

Beilstein J. Org. Chem. 2018, 14, 1537–1545, doi:10.3762/bjoc.14.130

• the desired transformation. As the calculated rate-limiting transition state TS3 benefits from a stabilization of the developing negative charge on the sulfonamide, the relative rates of Scheme 3 provide further support for the migratory insertion representing the rate determining step [44]. As

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• between heteroaryl bromides, chlorides or iodides and carbamate, sulfonamide or urea derivatives to be successfully realized in water using palladium-loaded TPGS-750-M (dl-α-tocopherol methoxypolyethylene glycol succinate) micelles (Scheme 1). Moreover, this micellar catalytic system allowed for catalyst

Synthetic and semi-synthetic approaches to unprotected N-glycan oxazolines

• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 416–429, doi:10.3762/bjoc.14.30

• the GlcNAc acceptor has an azide or sulfonamide at position 2, rather than acetamide or N-phthalamide. Scheme 5 shows an example of the synthesis of a modified core N-glycan tetrasaccharide oxazoline from the several reported by Wang [77] using this approach. In this case following formation of the

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

• development of chiral bifunctional urea 1 [35], thiourea 2 and 3 [36][37], sulfonamide 4 [38][39][40] and squaramide 5 [38][39][40] catalysts derived from chloramphenicol base (Figure 1), which showed excellent reactivity and enantioselectivity for this asymmetric transformation. A typical example of the

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• nature of the substituents of the sulfonamide group showed little influence on the efficiency of the process. On the contrary, better results were obtained when realising the reaction on substrates featuring electron-donating groups on the phenyl ring directly bound to the nitrogen atom. It was also

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres

• Myriam Drouin and
• Jean-François Paquin

Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262

• using a chiral sulfonamide as chiral auxiliary afforded 99 (de > 98:2). Finally, group manipulations, i.e., deprotection of the amine, Fmoc reprotection and oxidation gave the isostere 100. Then, Pannecoucke’s group proposed a modified and more versatile approach where the monofluoroalkene 102 was

Synthesis of benzannelated sultams by intramolecular Pd-catalyzed arylation of tertiary sulfonamides

• Valentin A. Rassadin,
• Mirko Scholz,
• Anastasiia A. Klochkova,
• Armin de Meijere and
• Victor V. Sokolov

Beilstein J. Org. Chem. 2017, 13, 1932–1939, doi:10.3762/bjoc.13.187

• formation of a 2,3-diarylindole was observed under the same conditions. Keywords: arylation; fused-ring systems; indole formation; palladium catalysis; sultams; Introduction The sulfonamide functional group stands out as one of the most important pharmacophores. At the same time, cyclic sulfonamides

• methyl iodide (Scheme 2). Unfortunately, this apparently simple transformation yielded a mixture of C-, N- and C,N-methylation products due to similar reactivities of the C- and N-nucleophilic centers in 3a. At best, the tertiary sulfonamide 5 was isolated in 32% yield. In contrast to the behavior of 3a

• problem in the alkylation of the sulfonamide 3a, the sequence of steps was reversed. Thus, 2-iodo-N-(4-methoxybenzyl)anilines 7a–g were prepared by reduction of the Schiff bases obtained from 2-iodoanilines 1a–g and 4-methoxybenzaldehyde with sodium cyanoborohydride in a mixture of glacial acetic acid and

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• potassium carbonate as the base was necessary to deprotonate the sulfonamide and thus increase its reactivity. After milling for 2 hours with the corresponding iso(thio)cyanate, the sulfonyl (thio)ureas 42a–c were isolated in excellent yields, for example the drug tolbutamide (1) in 92% (Scheme 17a

• sulfonamide–isocyanate coupling. The mechanochemical EDC-mediated amide bond formation [50] was successful and provided the intermediate 43 in 74% yield. In the second step, coupling of the sulfonamide intermediate 43 with 1.2 equivalents of cyclohexyl isocyanate in the presence of 5 mol % of CuCl and

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• conditions [90]. Key to success in this spectacular report was the use of the systematically optimized sulfonamide-containing phosphonium salt J1. With this catalyst, they were able to achieve high selectivities in the α-chlorination of 1 with N-chlorophthalimide (13) as the Cl-source under H2O-rich

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• ], or oxidised to oxaziridines used as efficient chiral oxidising reagents [13][17][18][19]. The reaction of the oxoimide 3 with two equivalents of the lithium salt of a terminal alkyne leads to compounds 4 where two alkynyl substituents, a sulfonamide and a hydroxy group are found in vicinal positions

• coincide in 13 but are approximately 2 ppm apart in 12. Compounds 12 show a signal for the C=O near 206 ppm and one for the sulfonamide carbon at about 65 ppm. In compounds 13, there is a signal for the C=N around 194 ppm and one for the tertiary alcohol carbon near 73 ppm. All other signals of the camphor

• in the presence of Zn/HOAc, as shown in Scheme 4. The product shows an IR stretching vibration at 1760 cm−1 and a 13C NMR signal at 209.7 ppm for the unreacted C=O group. The presence of the sultam can be deduced from the NH stretching vibration at 3180 cm−1, a 13C signal of the sulfonamide carbon at

DMAP-assisted sulfonylation as an efficient step for the methylation of primary amine motifs on solid support

• Johnny N. Naoum,
• Koushik Chandra,
• Dorit Shemesh,
• R. Benny Gerber,
• Chaim Gilon and
• Mattan Hurevich

Beilstein J. Org. Chem. 2017, 13, 806–816, doi:10.3762/bjoc.13.81

• introduction of the o- or p-nitrobenzenesulfonyl groups to primary amines in the first step. The semi-protected sulfonamides can then undergo a selective mono-methylation via Mitsunobu reaction or by direct methylation. The reaction is completed by the selective removal of the sulfonamide group. Miller and

Chromium(II)-catalyzed enantioselective arylation of ketones

• Gang Wang,
• Shutao Sun,
• Ying Mao,
• Zhiyu Xie and
• Lei Liu

Beilstein J. Org. Chem. 2016, 12, 2771–2775, doi:10.3762/bjoc.12.275

• ) was selected as the model reaction for optimization employing Kishi’s oxazoline/sulfonamides as the chiral ligands. A series of oxazoline/sulfonamide ligands (L1–L8) were tested and the results were summarized in Table 1. Four subgroups of R1 were studied (entries 1–4, Table 1) and isopropyl

• ) was used, enantiopure indan-1-ol was obtained in 70% yield and 82% ee. Conclusion In summary, we have developed the first Cr-catalyzed enantioselective arylation of ketones in an intramolecular version using oxazoline/sulfonamide L8 as the catalyst. Both aliphatic and arylaliphatic ketones proceeded

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• (1) and (±)-allo-enduracididine (3) reported by Du Bois et al. arose from the methodology for the conversion of alkenes to diamines via a cyclic sulfonamide intermediate using rhodium catalysis (Scheme 9) [63]. The reaction proceeds with formation of an intermediate aziridine 53 which rearranges upon

• addition of sodium iodide to afford the desired cyclic sulfonamide 54. For the synthesis of (±)-enduracididine (1) and (±)-allo-enduracididine (3), protected (±)-allylglycine 55 was treated with BocNHS(O)2NH2, MgO, Rh2(esp)2 and PhI(OAc)2 in isopropyl acetate followed by sodium iodide to afford cyclic

• sulfonamide 56 in 56% yield as a 1:1 mixture of diastereomers (Scheme 10). Selective deprotection of the sulfonamide Boc group allowed separation of diastereomers 57 and 58 via chromatography which were then converted to Tces (2,2,2-trichloroethoxysulfonyl) protected guanidines 59 and 60. Global deprotection

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• asymmetric redox bicycloisomerization of 1,6- and 1,7-enynes. This complex was used to synthesize a broad array of [3.1.0] and [4.1.0] bicycles. Sulfonamide- and phosphoramidate-containing products could be deprotected under reducing conditions. Catalysis performed with enantiomerically enriched propargyl

• steps. Heterocycle 7 is a bench stable white powder that can be stored indefinitely in a dessicator without any noticeable decomposition. The sulfonamide moiety activates sulfur towards nucleophilic addition, making the first addition of an organometallic reagent faster than the second. By performing

• decided to initiate our efforts on 1,7-enyne sulfonamide 13 for reaction optimization. Table 1 showcases our initial experiments. With 3 mol % of CpRu-sulfoxide catalyst 1 in THF at 40 °C, 14 could be obtained in a 69% yield and a promising 26.5:73.5 er (Table 1, entry 1). This important first experiment

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

• to the total synthesis of natural TMC-95A. In 2015, Yang and co-workers reported α-amino acid sulfonamide (cat. 7)-catalyzed aldol reactions of ketones with isatins under neat conditions (Scheme 20) [36]. Interestingly, the reactions proceeded smoothly, giving the desired products in high yields (up

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• generated the tosylamine-bridged bicycle 51. The aminal in 51 could be transformed to a methyl hemiaminal, and then later a second C–H bond insertion by another nitrene targeted the less activated C–H bond to form the ring-fused piperidine 52. Thus, the pendant sulfonamide acted as a tool for multiple

1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

• Antonia Mielgo and
• Claudio Palomo

Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90

• catalytic cycle, while providing the final product VIII. The authors propose a bifunctional behavior of the catalyst, wherein a hydrogen bonding interaction between the sulfonamide N–H and the thiazolone enolate controls its addition to the C–C double bond, which is the key step for asymmetric induction

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

• M. Fernanda N. N. Carvalho,
• M. João Ferreira,
• Ana S. O. Knittel,
• Maria da Conceição Oliveira,
• João Costa Pessoa,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2016, 12, 732–744, doi:10.3762/bjoc.12.73

• decarboxylation reaction (azomethine ylides 7 and ene-sulfonamide 8). Figure 11 shows the structures and relative energies of geometry-optimized isomeric primary products 7 and 8, as well as their tautomeric products 9, 10 and 11 containing the newly formed C–H bonds. These secondary isomers are considerably more

• of water is necessary for this step. 2. The fastest tautomerization in the reaction mixture occurs between 7a and 8 (the ene-sulfonamide). The low barriers (8.4 and 10.6 kcal/mol) should allow the equilibrium to be established rapidly. On the other hand, there is no possibility of proton transfer

• system as in ninhydrin. The resulting intermediates, azomethine ylides or ene-sulfonamide, undergo water-catalyzed tautomerization reactions followed by hydrolysis of the C=N bonds to form amines with a new chiral center at the former C=O group of compound 1. The isolated compound 2 is derived from one