Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• acid, trifluoroborate moiety, trifluoromethanesulfonate, aryl sulfonamides, and heterocycles, have been incorporated into the ortho-position of diaryliodonium structures [16][17][18][19][20][21]. Ortho-trimethylsilyl or boronic acid-substituted diaryliodonium salts can serve as aryne precursors. Ortho

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• with up to 10 mol % JPhosAu(NCCH3)SbF6 in CD2Cl2 after 48 hours with and without added CH3OH) despite common use of sulfonamides in alkene hydroamination reports, albeit at higher temperatures. Based on our ligand survey above, we proposed to improve rates of cyclization with slower reacting substrates

• ; there are similarities and differences in the way a sulfonamide or carbonyl impacts a neighboring nitrogen. Sulfonamides have different steric profiles from carbonyls [51]. According to Roush et al. the electron-withdrawing capability of the S(O2)Ph group is in between that of the C(O)Me and CO2Me

• groups as measured by rates of Michael addition [52]. This suggests that in fact nitrogen nucleophilicity alone is not the most relevant factor since sulfonamides react much slower in hydroamination. Sulfonamide N–H bonds are significantly more acidic than urea, amide and carbamate N–H bonds (16.1 versus

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• through concerted or stepwise mechanisms. An enantioselective palladium-catalyzed three-component reaction of glyoxylic acid, sulfonamides, and aryltrifluoroborates toward synthetically useful α-arylglycine compounds is described by the Manolikakes group [11]. Moreover, Šebesta and co-workers report a

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• under the reaction conditions and afforded the bromination products 3ua and 3va in 93 and 98% yield. Finally, some other acyl motifs were investigated (3wa–za) and the results showed that the protocol could be successfully applied to sulfonamides, albeit giving the target product 3za in only 53% yield

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

•  1). In our previous works, we have shown that the reaction of pyrrole with N-tosylimines leads to pyrrole sulfonamides as the main products [35]. In another work, in the synthesis of dipyrromethane structures, we have proven the formation of azafulvene intermediates by Cu(OTf)2-appended elimination

• of sulfonamide groups from pyrrolic sulfonamides [36]. Here in this work, during the reaction at 0 °C, intermediates I–VI were detected (Figure 1). The primary intermediates II and IV are formed by the addition of tripyrrane 1 to tosylimine 2d. Further elimination of N-tosyl group(s) from these

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• important factors, and the commonly utilized chemicals include thiols [16][17][18], disulfides [19][20][21][22], sulfenyl halides [23][24][25], sulfonamides [26], sulfenate esters [27][28], and methyl(bismethylthio)sulfonium salts [29][30]. Among various organic molecules, aryl sulfides are recognized as

• chlorinated product 21 was detected, which with POCl3 gave the cyclized product 22. Also, the synthesis of benzo[b]thieno[2,3-c]quinolone 24 as an anticancer molecule was demonstrated in this approach (Scheme 13). An intermolecular sulfenoamination of alkenes 9 with sulfonamides 25 as the nitrogen source and

• N-thiosuccinimides 1 as the sulfur source was reported by Gao and Liu et al. (Scheme 14) [52]. Highly regio- and diastereoselective β-sulfonylamino sulfides 26 were obtained from alkenes 9, N-thiosuccinimides 1, and sulfonamides 25 in the presence of 20 mol % BF3·Et2O. While the transformation in

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• (P2O5) as a catalyst for the conversion of various aliphatic amines, aromatic amines, sulfonamides and primary amides into N-substituted pyrroles (Scheme 5). These pyrroles were synthesized in 46–100% yields by the modified Clauson–Kaas reaction between amines 10 and 2,5-DMTHF (2) in the presence of

• their expectation thus, they synthesized 13 derivatives of pyrroles in good yields in short reaction times (10–45 min). It has been observed that aromatic amines and amides take a longer time compared to the primary amines and sulfonamides. In another study, Rochais et al. [59] reported in 2004 the

• Clauson–Kaas reaction in a successive cyclization/annulation process from commercially available sulfonamides 14 in the presence of trifluomethanesulfonic acid (TfOH) as Brønsted-acid catalyst. This procedure produces only N-substituted products and preserves other positions open for further

Facile access to 3-sulfonylquinolines via Knoevenagel condensation/aza-Wittig reaction cascade involving ortho-azidobenzaldehydes and β-ketosulfonamides and sulfones

• Ksenia Malkova,
• Andrey Bubyrev,
• Stanislav Kalinin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 800–807, doi:10.3762/bjoc.19.60

• Ksenia Malkova Andrey Bubyrev Stanislav Kalinin Dmitry Dar'in Saint Petersburg State University, Saint Petersburg 199034, Russian Federation 10.3762/bjoc.19.60 Abstract Quinoline-based sulfonyl derivatives, and especially sulfonamides, are relevant and promising structures for drug design. We

• have developed a new convenient protocol for the synthesis of 3-sulfonyl-substituted quinolines (sulfonamides and sulfones). The approach is based on a Knoevenagel condensation/aza-Wittig reaction cascade involving o-azidobenzaldehydes and ketosulfonamides or ketosulfones as key building blocks. The

• protocol is appropriate for both ketosulfonyl reagents and α-sulfonyl-substituted alkyl acetates providing the target quinoline derivatives in good to excellent yields. Keywords: aza-Wittig reaction; azides; cyclocondensation; quinolones; sulfonamides; Introduction The quinoline scaffold has a wide

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• condensation of aromatic aldehydes and sulfonamides (Scheme 1a) [3][5][6][7][8]. Because of the poor nucleophilicity of sulfonamides, the condensation reactions generally require harsh reaction conditions involving the use of strong acids, elevated temperature, and metal catalysts. Other methods include a non

• -dehydrative reaction of aldehydes with isocyanate analogs ([3] and references therein) (Scheme 1b) and an oxidative reaction of primary benzylic alcohols with sulfonamides or chloramine-T ([3] and references therein), and although they are elegant, they use substrates that are not readily accessible or toxic

Palladium-catalyzed enantioselective three-component synthesis of α-arylglycine derivatives from glyoxylic acid, sulfonamides and aryltrifluoroborates

• Bastian Jakob,
• Nico Schneider,
• Luca Gengenbach and
• Georg Manolikakes

Beilstein J. Org. Chem. 2023, 19, 719–726, doi:10.3762/bjoc.19.52

• , sulfonamides and aryltrifluoroborates is described. This process provides modular access to the important α-arylglycine motif in moderate to good yields and enantioselectivies. The formed α-arylglycine products constitute useful building blocks for the synthesis of peptides or arylglycine-containing natural

• products. Keywords: amino acids; asymmetric catalysis; multicomponent reaction; palladium catalysis; Petasis reaction; sulfonamides; Introduction α-Amino acids play a crucial role in every aspect of our human life [1]. They are important synthetic intermediates in the chemical industry and used for the

• palladium-catalyzed three-component reactions between arylboronic or carboxylic acids, amides or sulfonamides and different aldehyde components as attractive and broadly applicable alternative to the classical Petasis borono-Mannich reaction (Scheme 1b) [17][18][19][20][21]. Recently, we were able to extend

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• transformations. For example, bromoacetylenes were demonstrated to add imidazoles, imidazolines [12], and benzimidazoles [13][14] to give vinyl bromides. Sulfonamides reacted with bromoacetylenes to deliver N-bromovinyl-p-toluenesulfonamides that under Heck reaction conditions afforded N-(p-toluenesulfonyl

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• , sulfonyl chlorides are good building blocks to intermediates and complex scaffolds of sulfonamides. Gordon, Maskill, and Ruasse [1] have reviewed “Sulfonyl Transfer Reactions” in a broader sense than the coverage of the present contributions. In particular, an appreciable amount of the coverage in the

DABCO-promoted photocatalytic C–H functionalization of aldehydes

• Bruno Maia da Silva Santos,
• Mariana dos Santos Dupim,
• Cauê Paula de Souza,
• Thiago Messias Cardozo and
• Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

• very attractive as HAT catalysts as demonstrated by previous works using secondary amides [8][9], sulfonamides [10] and quinuclidine [11][12], the latter being broadly explored in the literature for several functionalizations along with its derivatives [11][12][13][14][15][16][17][18][19][20]. DABCO is

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• catalyst wasn’t necessary to promote the reaction, but the yield of the cascade was significantly increased upon loading. The scope of the π-systems was limited to alkenes conjugated to electron-rich aryl species. Various nitrogen nucleophiles including primary/secondary amines and sulfonamides were

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• of carbamates, sulfonamides and acetamides 13 bearing an α,β-unsaturated ketone to synthesize a series of 2-substituted five- and six-membered heterocycles in good yields (up to 99%) and excellent enantioselectivity (92–97.5% ee) (Table 3). As in an earlier case [29], several acids were tested as co

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• showcase his methodology, they first synthesized acyclic optically active N-fluoro sulfonamides 27-7–9 (Scheme 62) and attempted the enantioselective fluorination of some enolates in 1997 [92]. However, the best result was an enantiomeric excess of 48% with a chemical yield of 53% after the enolate anion

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• %) from allylic sulfonamides 40 and Togni’s reagent (41). The reaction mechanism is proposed based on DFT calculations. In this study, they observed an intramolecularly intermediate Cu(III) species, and the sulfinamide acts as a direction group and nucleophile [75] (Scheme 14). Asymmetric synthesis of

The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

• Deniz Tözendemir and
• Cihangir Tanyeli

Beilstein J. Org. Chem. 2021, 17, 494–503, doi:10.3762/bjoc.17.43

• simultaneous activation of both the nucleophile and the electrophile [12][13][14][15]. Quinine derived sulfonamides were first introduced to the literature by Song et al. [16]. Since then, many contributions were made regarding their applications in a variety of reaction types [17][18][19][20]. However, sulfa

• outshined by sulfonamides in medicinal chemistry, they have a large array of biologic activities that show promising effects as potent anti-HIV-1 [34], anti-hepatitis C [35], antifungal [36], insecticidal/acaricial [37] and antimalarial [38] agents. Results and Discussion We have previously reported the

• synthesis of new amino-substituted-DMAP-based sulfonamides [39] and quinine-based squaramide-type organocatalysts [40]. Motivated by the excellent results obtained with our aforementioned catalysts, we developed a new chiral bifunctional sulfonamide–quinine organocatalyst that unites both classes. The

Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates

• Hisham Qrareya,
• Lorenzo Meazza,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 3008–3014, doi:10.3762/bjoc.16.250

• two aromatic rings to direct the selective Ar–Ar bond formation (Scheme 1b) [41][42][43]). In this case, N-methyl sulfonamides were the elective substrates albeit a part of the tether is maintained in the final structure. This is common even for other related metal-free biaryl syntheses exploiting the

• Truce–Smiles rearrangement in aryl sulfonamides and aryl phenylsulfonates [44][45][46] or the [3,3]-sigmatropic rearrangement of sulfonium salts arising from the reaction of aryl sulfoxides and phenols [47]. To overcome this problem, the use of a metal catalyst (mainly Ni) was mandatory as reported for

• the real extrusion of CO in diaryl ketones [48][49] or of SO2 in diaryl sulfones (Scheme 1c) [50]. Nevertheless, a recent publication demonstrated that a metal-free photoextrusion was feasible when starting from benzene sulfonamides I (Scheme 1d, path a) [51]. Following the same approach, sparse

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• :4. Recently, Knowles et al. used a similar tricatalytic system for the enantioselective cyclisation of sulfonamides 238 (Scheme 37) [98]. In this case, the proposed mechanism involves a PCET step to give an N-centred radical that then cyclises enantioselectively to give the alkyl radical

• intermediate 239•, which abstracts a hydrogen atom from TRIP-thiol to produce enantioenriched cyclic sulfonamides 239 in excellent yields and enantioselectivities (28 examples, up to 98:2 er). Chiral phosphates have also been used to catalyse the enantioselective nucleophilic addition of indoles 241 to imines

A complementary approach to conjugated N-acyliminium formation through photoredox-catalyzed intermolecular radical addition to allenamides and allencarbamates

• Olusesan K. Koleoso,
• Matthew Turner,
• Felix Plasser and
• Marc C. Kimber

Beilstein J. Org. Chem. 2020, 16, 1983–1990, doi:10.3762/bjoc.16.165

• the γ-position [37][39][40]. An examination of the allenamide unit under these conditions is shown in Scheme 4, and the six allenylamides/sulfonamides (15, 21–25) were prepared using known conditions [52][53]. The allenamides derived from pyrrolidinone (21), piperidinone (22) and oxazolidinone (15

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• sulfonamides 47, followed by the introduction of the fluoroallyl group via N-alkylation with previously described mesylate 38 provided fluorinated enynes 48 (Scheme 24). The enantioenriched starting materials 48 were then evaluated in the Co-mediated PKR to yield the bicyclic products 49 in moderate to good

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• rise to 3-heteroarylthietanes 403 and 404, respectively [109][110] (Scheme 85). The treatment of various N-substituted sulfonamides 405 with chloromethylthiirane (398a) in the presence of KOH in water gave rise to the corresponding 3-sulfonamidothietanes 406 in low to moderate yields [111] (Scheme 86