Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

• co-workers [117] explored a simple and facile method to access δ-trifluoromethylated carboxamides and sulfonamides through a copper-catalyzed 1,5-hydrogen atom transfer (Scheme 58). Other catalysts: In 2013, Gouverneur and co-workers [118] described a photoredox-based catalytic approach to afford

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• . The Pd-catalyzed Sonogashira reaction has successfully constructed arylated internal alkynes that are important intermediates in organic synthesis, molecular electronics and polymers [56]. C–N bond forming reactions between aryl halides and amines/amides/sulfonamides have been extensively studied in

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

• perflurophenylboronic acid as a versatile organocatalyst for the Ferrier rearrangement reaction. We noted that the yields of the disaccharides 3n and 3o and sulfonamides 3t and 3u can be increased with increase in the temperature (60 °C) and extension of the reaction time. The results in Table 1 are superior to the

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• metal catalyst. Through a tandem three-component cross-dehydrogenative coupling (CDC), they prepared, in a single step, more than thirty isoindolinone derivatives 4, including those originated from sulfonamides and carboxamides (Scheme 1). The scope of the reaction includes aromatic, some aliphatic and

• three-component reaction between aryl iodides, incorporating a Michael acceptor 105, amines and amides 2 and carbon monoxide (23) (Scheme 30) [108]. It is remarkable that not only aromatic but also aliphatic amines and even amides and sulfonamides can be used as the nitrogen-containing substrate. With

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• ]. A limited number of derivatizations of anacardic acid are reported by now, including the synthesis of lactones [18][19][20], sulfonamides [21] or hydrazones [22], typically bioactive compounds though with low commercial value. However, several studies suggest that anacardic acid and its derivatives

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

• ]. Both approaches were then combined into low molecular weight C-glycosidic sulfonamides, which resulted in very potent LecB and P. aeruginosa biofilm inhibitors with over 80% inhibition at a concentration of 100 µM [50]. Compound 18 of this series further showed very good in vitro stability against

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

• . Synthesis of miscellaneous spirocyclic compounds 5.1. Using stoichiometric amounts of iodine(III) reagents In 2002, Ciufolini and co-workers [123] reported the spirocyclization of various phenolic sulfonamides 122 to spiropyrrolidines 123 using PIDA (15). In this reaction, sulfonamides 122 undergo N

• -acylation, wherein various homotyramine sulfonamides were treated with electrophile PIDA (15) in hexafluoroisopropanol to give the spirocyclic products 123 in high yields (Scheme 45). However, the similar spirocyclization could not successfully applied for the construction of six-membered spiropiperidine

• 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

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• been reported (Scheme 27) [67]. A variety of amines such as anilines, sulfonamides and aliphatic amines has been utilized though in large excess. But in contrast to the previous method, electron-rich anilines proved to be better candidates for this reaction than the electron-poor analogs. The group of

• ]. Seminal catalytic nitrene transfers mediated by λ3-iodanes [86][87][88][89] were described from iminoiodinanes of general formula PhI=NR that can be prepared mainly from sulfonamides [90]. However, the scope of catalytic C(sp3)–H amination and alkene aziridination reactions has been greatly enhanced

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

• -derived bifunctional derivatives catalyzed asymmetric alcoholysis of anhydride, the exploration of new effective and easily accessible fully synthetic organocatalysts through further modification of this privilege motif are always needed. Our present design is inspired by cinchona-derived sulfonamides

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• alkynes, bearing electron-donating (methyl, methoxy, amine or hydroxy) and withdrawing substituents (halides, carbonyls or sulfonamides) and also heterocyclic substrates. Various aromatic sulfinic acids could be applied, including methoxy, halogen, trifluoromethyl or acetylamino-substituted benzenes, as

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

• examples [25][26]. More recently, Zard et al. have developed a sequence of lauroyl peroxide-catalyzed radical additions of xanthate to substituted N-aryl vinyl sulfonamides and subsequent intramolecular cyclization to yield benzo-annelated γ-sultams [27]. Quite interestingly, the obtained sultams were

• efficiently used for the preparation of ortho-functionalized anilines. This contribution deals with a new access to ring-annelated sultams by an intramolecular Pd(0)-catalyzed arylation of tertiary sulfonamides bearing an additional C–H acidic center (Scheme 1). From several potentially suitable electron

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

• , aliphatic amines and sulfonamides worked smoothly under these conditions to obtain the desired product in 3 h. They have also extended the methodology for the synthesis of tetrahydroisoquinoline by using o-formyl phenethyl bromide with amine and KCN (Scheme 30) [120]. Since the discovery in 1890, the

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

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

• chlorpropamide or the 2nd generation drugs like glibenclamide (Figure 1). These molecules were interesting synthetic targets for our mechanochemical approach which is based on a stoichiometric base-assisted or copper-catalyzed coupling of sulfonamides and iso(thio)cyanates [48]. For that purpose, 0.5–1 equiv of

• -sensitivity and corrosive nature of the sulfonyl isocyanate reagent. In addition, these reagents are generally unavailable in comparison with sulfonamides, many of which are air-stable commercial chemicals [49]. In order to avoid using stoichiometric quantities of a base, a mechanochemical catalytic approach

• synthesis of guanidines Guanidines The success of mechanochemical synthesis of sulfonylureas by the coupling of sulfonamides with isocyanates led us to investigate the reactivity of sulfonamides with carbodiimides as another example of the heterocumulene system [52]. The attempted addition of p

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

• supported by the IR spectrum. Only one S=O vibration can be identified at 1098 cm−1, in a similar position as the S=O vibrations in DMSO (1050 cm−1) or tert-butylsulfinamide (1032 cm−1) [43]. The strong band at about 1330 cm−1, typical for the asymmetric S=O stretch in sulfonamides and sulfones, is absent

• groups, but there is a medium intense C=C stretching vibration at 1653 cm−1 and two strong bands at 1324 cm−1 and 1059 cm−1 for the asymmetric and symmetric stretches of the O=S=N moiety. Compared to the SO2 moiety in sulfonamides (e.g., 21b with 1330 cm−1 and 1128 cm−1) the symmetric stretch is 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

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

•  41). The regioselectivity was maintained in the presence of various functional groups. Further studies revealed that several functional groups such as esters, amides and sulfonamides could be added to the list of directing groups. The Dong group reported a similar work and developed two types of

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

• in 30 minutes from 7a. While increasing the reaction time from 30 minutes to 2 h, the formation of biologically active pyrazinone 10a has been realized as a major product along with ene-diamide 9a. A literature survey revealed that sulfonamides are known to undergo hydrolysis in the presence of a

• Brønsted acid [32]. Sulfonamides also participate in amide hydrolysis with external nucleophiles such as phosphide anions [33] or phenyldimethylsilyllithium [34]. The combinations of thiophenol/K2CO3 [35] or NaOH/MeOH [36] are also known to hydrolyse sulfonamides. These methods lead to the formation of the

• corresponding free amines. Such desulfonylation of sulfonamides has been less utilized to make an unsaturated bond, for example, imine. Hence, attention has been paid to find suitable conditions for the formation of pyrazinones directly from piperazine-2,6-diones via cyclization followed by dehydrosulfonylation

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

• Arno Verlee,
• Thomas Heugebaert,
• Tom van der Meer,
• Pavel I. Kerchev,
• Frank Van Breusegem and
• Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

• amines, a decrease in substrate concentration was essential to selectively obtain amides over sulfonamides. It was shown that the procedure can easily be used for the synthesis of a compound library suitable for initial screening; and that the optimized synthetic conditions are directly transferrable

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

Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

• Kevin Lafaye,
• Cyril Bosset,
• Lionel Nicolas,
• Amandine Guérinot and
• Janine Cossy

Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241

• including alcohols, halides, esters, amides, carbamates and sulfonamides are compatible with the metathesis conditions [14][15][16][17][18][19][20]. However, the involvement of alkenes containing a nitrogen atom such as an amine or an N-heteroaromatic ring in metathesis reactions is still problematic and

• allow the use of primary and secondary amines in ring-closing metathesis (RCM) and cross-metathesis (CM), and one of them is the transformation of amines into carbamates, amides or sulfonamides [27][28][29]. As an alternative, metathesis reactions can be performed with olefins possessing ammonium salts

Recent advances in copper-catalyzed C–H bond amidation

• Jie-Ping Wan and
• Yanfeng Jing

Beilstein J. Org. Chem. 2015, 11, 2209–2222, doi:10.3762/bjoc.11.240

• adjacent to oxygen via an N-halosuccinimide- (NCS or NBS)-assisted copper-catalyzed process. As shown in Scheme 2, both cyclic and acyclic compounds 6 containing a benzylic C–H bond could be readily converted to N-alkylamides 8 or sulfonamides 9 via this much milder catalytic method. In addition, this

• or secondary sulfonamides 15 with the assistance of 1,10-phenanthroline as a ligand (Scheme 3). Notably, the asymmetric version of a similar amidation had been previously achieved by Clark et al. via copper catalysis in the presence of a chiral oxazoline ligand, which allowed the synthesis of

• reaction at 100 °C allowed the synthesis of various N-alkylamides, sulfonamides and imides with fair to excellent yield, and the results also suggested that the catalytic method tended to selectively enable the transformation of secondary or primary C–H bonds, while the amidation of the tertiary alkyl C–H

Recent applications of ring-rearrangement metathesis in organic synthesis

• Sambasivarao Kotha,
• Milind Meshram,
• Priti Khedkar,
• Shaibal Banerjee and
• Deepak Deodhar

Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199

• catalyst 7. Pyrrolines were produced in excellent yields by RRM of sulfonamides 31a,b using the catalyst 2 under dichloromethane reflux conditions (32a 99%, 32b 70%) (Scheme 3). Five-membered heterocycles such as 34 and a seven membered heterocycle 35 in 40:60 ratio (97%) were formed by RRM of

Fates of imine intermediates in radical cyclizations of N-sulfonylindoles and ene-sulfonamides

• Hanmo Zhang,
• E. Ben Hay,
• Stephen J. Geib and
• Dennis P. Curran

Beilstein J. Org. Chem. 2015, 11, 1649–1655, doi:10.3762/bjoc.11.181

• Hanmo Zhang E. Ben Hay Stephen J. Geib Dennis P. Curran Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA 10.3762/bjoc.11.181 Abstract Two new fates of imine intermediates formed on radical cyclizations of ene-sulfonamides have been identified, reduction and hydration

• ; radical cyclization; radical fragmentation; spiro-indoles; Introduction Radical additions and cyclizations of ene-sulfonamides are useful reactions in a number of settings. The primary products of these reactions, α-sulfonamidoyl radicals, are often thought to undergo elimination reactions of sulfonyl

• radicals to make transient imines [1][2][3]. In turn, onward reactions of the imines provide assorted products including ketones and nitrogen heterocycles [4][5][6][7][8][9][10]. Figure 1a shows a generic addition/elimination reaction of ene-sulfonamides along with example transformations in Figure 1b from

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

• Gerold Heuger and
• Richard Göttlich

Beilstein J. Org. Chem. 2015, 11, 1226–1234, doi:10.3762/bjoc.11.136

• has been achieved by Zhang [22] using copper or palladium catalysts and proceeds via radicals and fluoropalladation, respectively. Cyclisation reactions of unsaturated sulfonamides which proceed via amidyl radicals have been described by Li [23] and by Oshima [24]. Chemler [25][26] discusses radical