Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• generation of alkyl radicals [39]. After that, a series of methods for the modification of alkylthianthrenium salts have been developed, including the transition-metal-catalyzed cross-coupling with terminal alkynes [40], sulfonylation with DABCO·(SO2)2 [41][42][43], or alkylation of active alkenes [44][45

Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions

• José G. Hernández,
• Karen J. Ardila-Fierro,
• Dajana Barišić and
• Hervé Geneste

Beilstein J. Org. Chem. 2022, 18, 182–189, doi:10.3762/bjoc.18.20

• ; sulfonylation; Introduction Mechanosynthesis of organic molecules and materials using mechanochemical techniques such as ball milling, extrusion, grinding, etc. [1][2][3] have enabled the development of known and new chemical transformations in a more sustainable fashion [4]. Commonly, mechanochemical

• functionalizations [22][23]. In particular, efficient fluorination protocols are long sought after in several areas of science, including medicinal chemistry [24]. Next to fluorination, in this work, we also have investigated NFSI as a source for mechanochemical sulfonylation of imidazoles and amidation reactions

• its N-methylated derivative 3b, a substrate unable to undergo the sulfonylation pathway with NFSI. We hypothesized that PhSO2F could have been generated after an initial reaction of the nitrogen with the lone electron pair in imidazole at the sulfonyl group of the NFSI (Scheme 3c), mimicking the

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• 402160, China 10.3762/bjoc.17.193 Abstract Chemoselective sulfonylation and isonitrilation reactions for the divergent synthesis of valuable diarylmethyl sulfones and isonitrile diarylmethanes starting from easy-to-synthesize para-quinone methides (p-QMs) and commercially abundant p

• report the chemoselective sulfonylation and isonitrilation of p-QMs by changing the reaction conditions. This new general protocol allows, from the same substrates p-QMs 1 and p-tosylmethyl isocyanide (TosMIC, 2a), the formation of quite different products 3 or 4 in a simple and mild manner, which

• , the reaction also proceeded, however, the reaction efficiency was lower compared to DBU (Table 1, entry 11). After identifying the optimal conditions, we first evaluated the substrate scope of the sulfonylation reaction. As shown in Scheme 2, various substituted p-QMs were readily transformed in this

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

• benzothiazole and benzimidazole-based sulfonylguanidine compounds were derived by the sulfonylation of the corresponding 2-guanidinobenzazoles and assayed as potential antimelanoma agents (Scheme 11C) [33]. Of note, a dearomatization of the benzothiazole ring was observed while grafting a sulfoguanidinyl group

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• alkynylation of cyclopropanes 161 with terminal alkynes that led to the formation of the isomeric fluorinated enynes 164 and 165. Shortly before, a Pd-catalyzed ring-opening sulfonylation of gem-difluorocyclopropanes with the formation of 2-fluoroallylic sulfones 166 has been reported (Scheme 71) [122]. The

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• a mild and efficient protocol for the remote C4–H sulfonylation of 1-naphthylamine derivatives with sodium sulfinates in the presence of K2S2O8 as the oxidant (Figure 35) [99]. This strategy was based on the use of a bidentate picolinamide DG promoting the direct C–H functionalization of the

• naphthalene ring. The transformation proceeded under either Cu/Ag co-catalysis or using the dual Ru/Cu photoredox system. In the latter case, the methodology was operative at room temperature within a short reaction time, affording the desired products in good to excellent yields. The described sulfonylation

• reaction occurred smoothly on a gram scale and the DG could be subsequently removed by hydrolysis, further demonstrating the synthetic potential of this protocol. The authors proposed a plausible mechanism involving a radical pathway and suggested that this C4–H sulfonylation reaction might proceed via a

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• )phenanthridines via C–S bond formation. A typical case is shown in Scheme 16, path b. The process was initiated by the reduction of tosyl chloride (Ts–Cl) by a RuII-based photocatalyst. The resulting sulfonyl radical afforded phenanthridine 16.3b in a very good yield [83]. A related sulfonylation process was

• sulfonyl radical, prone to start a tandem sulfonylation/annulation of vinyl azides [84]. Recently, the phenanthridine core was assembled through a radical cascade triggered by the trifluoromethylthiolation of N-(o-cyanobiaryl)acrylamides. The process occurred under visible-light irradiation (6 W blue LED

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

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

Oxidative radical ring-opening/cyclization of cyclopropane derivatives

• Yu Liu,
• Qiao-Lin Wang,
• Zan Chen,
• Cong-Shan Zhou,
• Bi-Quan Xiong,
• Pan-Liang Zhang,
• Chang-An Yang and
• Quan Zhou

Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23

• sulfonylation of teriary cyclopropanols 91 with sodium sulfinates 129 for the synthesis of γ-keto sulfones 130 in excellent yields (Scheme 34) [114]. The reaction was compatible with a series of fluoroalkyl, aryl and alkyl sulfinate salts. Notably, oxygen instead of THBP as oxidation was viable in this

• -isocyanobiphenyls. Ag(II)-mediated oxidative ring-opening/fluorination of cyclopropanols with AgF2. Cu(II)-catalyzed ring-opening/fluoromethylation of cyclopropanols with sulfinate salts. Cu(II)-catalyzed ring-opening/sulfonylation of cyclopropanols with sulfinate salts. Na2S2O8-promoted ring-opening/arylation of

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

• Iveta Tichá,
• Gábor Benkovics,
• Milo Malanga and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2018, 14, 2829–2837, doi:10.3762/bjoc.14.261

• regioisomers on the primary rim of homobifunctionalized diazido-α-CDs by selective substitution on the primary rim. Specifically, three positional regioisomers 6A,6B-, 6A,6C-, and 6A,6D-diazido-α-CDs were prepared via different intermediates (using sulfonylation with capping agents, bromination and tosylation

• sulfonylation agent, dibenzofuran-2,8-disulfonyl chloride, but observed only a negligible selectivity towards the AC regioisomer. Notwithstanding, these researchers were more successful in achieving selectivity for the AB regioisomer by introducing auxiliary groups (phthalimide) [19]. Armspach et al

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• approach was recently adopted in a total synthesis of aurantoside G, involving the Mitsunobu ligation of a D-xylopyranose derivative 116 and N-nosylated methyl asparaginate 117 to give 118 (Scheme 22) [87]. Compared to N-sulfonylation, N-carbamoylation can also prove effective to enhance the acidity of a

Phosphoramidite building blocks with protected nitroxides for the synthesis of spin-labeled DNA and RNA

• Timo Weinrich,
• Eva A. Jaumann,
• Ute M. Scheffer,
• Thomas F. Prisner and
• Michael W. Göbel

Beilstein J. Org. Chem. 2018, 14, 1563–1569, doi:10.3762/bjoc.14.133

• . Results and Discussion To prepare compound 5, the deoxyuridine derivative 9 [44] was activated by sulfonylation and then treated with the protected TEMPO building block 10 [43] to provide 11 (Scheme 1). After deacetylation, phosphitylation of 12 straightforwardly led to amidite 5 in multigram amounts. In

• contrast to the corresponding nitroxide, all NMR spectra of 5 are well resolved indicating the absence of any paramagnetic moiety. Unlike compound 9, the corresponding inosine derivative is known to produce a mixture upon sulfonylation [30], a reaction giving poor yields in our hands. We therefore used the

Rapid transformation of sulfinate salts into sulfonates promoted by a hypervalent iodine(III) reagent

• Elsa Deruer,
• Vincent Hamel,
• Samuel Blais and
• Sylvain Canesi

Beilstein J. Org. Chem. 2018, 14, 1203–1207, doi:10.3762/bjoc.14.101

• . Extension of the method. Carbon-based nucleophiles. THF ring opening. Oxidative sulfonylation process mediated by iodine and iodine derivatives. Scope and limitations of the process. Supporting Information Supporting Information File 120: General procedures, synthesis of the products, spectroscopic data

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• -bromo-2´-deoxyuridine (Scheme 2) [41]. Compounds 3 and 4 were reacted with acetic anhydride in pyridine to protect the deoxyribose hydroxy groups. The O4 position was then activated by sulfonylation using 2-mesitylenesulfonyl chloride. The subsequent condensation with the appropriate 2-aminothiophenol

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

• selenosulfonates Formation of sulfone derivatives Already in 1994, the group of Barton envisioned that the photoreduction of selenosulfonates by [Ru(bpy)3]Cl2 as photoredox catalyst could lead to reactive sulfonyl radicals (Scheme 50) [87]. They were the first to report on a visible-light induced sulfonylation of

• ]. Two examples, norbonene and styrene, were presented and [Ru(bpy)3]Cl2 was used as photoredox catalyst. The groups of Zhang and Yu reported two additional photoredox-catalyzed methods for the sulfonylation of olefins. In their first paper they applied enamides as olefins, which were sulfonylated to the

• ) cyclic enamides, different N-vinyllactams and enecarbamates. Short time later, they applied this concept for the sulfonylation of enol acetates and observed the formation of β-ketosulfones (Scheme 52b) [90]. Again electron-rich, neutral and electron-deficient (hetero)arylsulfonyl chlorides were tolerated

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

• ]. These sulfonylation reactions will not be further detailed hereafter. Instead, CF3SO2Cl, which is experiencing an advanced level of growth for the installation of the CF3 moiety onto a wide range of substrates, alone or simultaneously with the chlorine atom or the sulfonyl group, is the focus of this

• of chlorination of carbanions was calculated to be more than 105 higher than that of the sulfonylation of methanol. However, forty years later, Shainyan and Danilevich reported that the process might not be that selective in regard to mono- versus dichlorination of compounds carrying two acidic

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• reactions, the versatility of these two reagents is presented in other reactions such as sulfonylation and chlorination. This first part is dedicated to sodium trifluoromethanesulfinate. Keywords: fluorine; sulfur; trifluoromethylation; trifluoromethylsulfenylation; trifluoromethylsulfonylation

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

• decomposition of the sulfonyl chloride 2a and did not improve the yield of the target product. However, sulfonylation of 7a can be achieved with two equivalents of 2a in MeCN in the presence of pyridine at 60 °C for 2 days to give the sulfonamide 8a in an acceptable yield of 46%. Employing these conditions

• , methyl 2-[N-(2-iodo-4-methylphenyl)-N-(4-methoxybenzyl)sulfamoyl]acetate (8b) and methyl 2-[N-(4-chloro-2-iodophenyl)-N-(4-methoxybenzyl)sulfamoyl]acetate (8c) could be prepared in 52 and 62% yield, respectively (Scheme 3). In a recent paper Xu et al. report sulfonylation of sluggish anilines with

• inseparable mixture. To further test the scope and limitations of this cyclization with respect to other C–H acidifying groups (EWG) on the tether, the α-toluenesulfonamide 12 was prepared in two steps from o-iodoaniline (1a, Scheme 5). The subsequent sulfonylation of 1a with α-toluenesulfonyl chloride

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

• several primary amine motifs, largely due to inefficient sulfonylation. Here we show that using the superior nucleophilic base DMAP instead of the commonly used base collidine as a sulfonylation additive is essential for the introduction of the o-NBS group to these amine motifs. DFT calculations provide

• an explanation by showing that the energy barrier of the DMAP intermediate is significantly lower than the one of the collidine. We demonstrate that using DMAP as a sole additive in the sulfonylation step results in an overall effective and regioselective N-methylation. The method presented herein

• proved highly efficient in solid-phase synthesis of a somatostatin analogue bearing three Nα-methylation sites that could not be synthesized using the previously described state-of-the-art methods. Keywords: N-methylation; nucleophilic addition; solid phase; somatostatin; sulfonylation; Introduction

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

• of sulfonylation. To improve the chemoselectivity when using secondary amines, an additional screening was performed with azepane and aniline as first and second reagent, respectively. Initially, we tried to increase the selectivity by decreasing the temperature. Unfortunately, the reaction mixtures

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

• Weinreb amide. Indeed, the use of N-methyl-3-phenyl-N-tosylbutanamide for this purpose was already reported by Itoh and coworkers [10]. However, a systematic study using simple amides has not yet been performed. In this context, we examined the sulfonylation and chemical conversion of N-methylated

• (100 MHz, CDCl3, TMS) δ 11.4 (CH3), 22.7 (CH2), 41.2 (CH2), 99.2 (CH), 126.0 (CH), 126.9 (C), 129.1 (CH), 130.7 (CH), 158.9 (C), 159.3 (C), 171.5 (C). Versatile functionalized nitrile oxides. A strategy for developing functionalized nitrile oxides. Sulfonylation of N-methylamides. Chemical conversions

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

Exploration of an epoxidation–ring-opening strategy for the synthesis of lyconadin A and discovery of an unexpected Payne rearrangement

• Brad M. Loertscher,
• Yu Zhang and
• Steven L. Castle

Beilstein J. Org. Chem. 2013, 9, 1179–1184, doi:10.3762/bjoc.9.132

• to BCl3 at low temperature [36]. Camphorsulfonic acid was also effective for this transformation, although lengthy reaction times were required. Treatment of the resulting diol 28 with 2,4,6-triisopropylbenzenesulfonyl imidazole (TrisIm) effected regioselective sulfonylation (presumably of the less

Use of 3-[¹⁸F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides

• Reik Löser,
• Steffen Fischer,
• Achim Hiller,
• Martin Köckerling,
• Uta Funke,
• Aurélie Maisonial,
• Peter Brust and
• Jörg Steinbach

Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115

• (Scheme 3). In contrast, its reaction with aniline derivatives required a longer time and led to the formation of side products that were identified as the corresponding N,N-bissulfonylanilines 16a–18a. The double sulfonylation of aromatic amines under strongly basic conditions was described earlier [29

• nucleophilic to undergo sulfonylation readily within short reaction times of 2–3 min. In contrast, the presence of these agents proved to be beneficial for the reaction of [18F]10 with aniline and 4-fluoroaniline (Table 2 and Figure 5A) and the well known acylation catalyst DMAP was somewhat advantageous over

• nucleophilic amines such as 4-nitroaniline. The reason for the beneficial effect of potassium trimethylsilanolate on the sulfonylation reaction could be a partial deprotonation of the 4-nitroaniline as the basicity of siloxides is comparable to that of alkoxides [39]. A pKa value of 21 has been reported for