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

Preparation and ring-opening reactions of N-diphenylphosphinyl vinyl aziridines

• Ashley N. Jarvis,
• Andrew B. McLaren,
• Helen M. I. Osborn and
• Joseph Sweeney

Beilstein J. Org. Chem. 2013, 9, 852–859, doi:10.3762/bjoc.9.98

• -sulfonylation in aziridine chemistry, due to the ability of the group to activate the ring and the relative ease of its removal at the conclusion of a synthetic manipulation. We report here in full [30] the results of our studies on the synthesis of N-Dpp vinyl azidirines, and selected ring-opening reactions of

Exploring chemical diversity via a modular reaction pairing strategy

• Joanna K. Loh,
• Sun Young Yoon,
• Thiwanka B. Samarakoon,
• Alan Rolfe,
• Patrick Porubsky,
• Benjamin Neuenswander,
• Gerald H. Lushington and
• Paul R. Hanson

Beilstein J. Org. Chem. 2012, 8, 1293–1302, doi:10.3762/bjoc.8.147

• nucleophilic aromatic substitution (SNAr) diversification pathway is reported. Eight benzofused sultam cores were generated by means of a sulfonylation/SNAr/Mitsunobu reaction pairing protocol, and subsequently diversified by intermolecular SNAr with ten chiral, non-racemic amine/amino alcohol building blocks

• , namely sulfonylation, Mitsunobu alkylation and SNAr, which when combined in different sequences or with different coupling reagents, give access to skeletally diverse sultams, including the title compounds and the 8-membered bridged, benzofused sultams [32]. Building on this strategy, we herein report

• on multigram scale through the use of three efficient steps, namely sulfonylation, Mitsunobu alkylation and SNAr, to generate both stereoisomers of each core [37] (Scheme 2). The bridged benzofused sultam scaffolds were prepared by a sulfonylation intramolecular SNAr protocol, reported previously [32

An intramolecular inverse electron demand Diels–Alder approach to annulated α-carbolines

• Zhiyuan Ma,
• Feng Ni,
• Grace H. C. Woo,
• Sie-Mun Lo,
• Philip M. Roveto,
• Scott E. Schaus and
• John K. Snyder

Beilstein J. Org. Chem. 2012, 8, 829–840, doi:10.3762/bjoc.8.93

• condensation with different solvents was needed to optimize the triazine formation. Sulfonylation of the indole nitrogen also proceeded routinely to give triazine 8a (R1 = H, R2 = p-Tol), and served two purposes. As noted, the reduction of electron donation from this nitrogen into the triazine ring was thought

• to be important for the subsequent cycloaddition to proceed, as was shown to be correct in later studies. Furthermore, sulfonylation greatly improved the solubility of the triazines 8 in organic solvents in comparison to 9, which showed only limited solubility in dichloromethane, chloroform, THF

Anion receptors containing thiazine-1,1-dioxide heterocycles as hydrogen bond donors

• Hong-Bo Wang,
• James A. Wisner and
• Michael C. Jennings

Beilstein J. Org. Chem. 2010, 6, No. 50, doi:10.3762/bjoc.6.50

• typically been realized synthetically by sulfonylation of an amine to form a sulfonamide product. This approach is somewhat limited, from a design perspective, in that the majority of examples to date consist of sulfonamides derived from a few commercially available starting materials such as

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• ]paracyclophane compounds; aryl sulfonylation and the related sulfenylation facilitates the synthesis of sulfonic acids, sulfonamides and protected thiols [24][25][26] whilst directed metallation has allowed the formation of various sulfides [27][28][29][30]. Very few methodologies allow the synthesis of simple