Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• thiahelicene, a class of typical heterohelicenes, has led to the preparation of symmetric thiophene-based [5]-, [7]-, [9]-, and [11]helicenes [9][10][11][12][13][14][15][16], unsymmetric thiophene-based [7]helicenes [17], and thiophene-based double helicenes with spiro-silicon atoms [18], “saddle” formed 8π

• , Figure S20, Table S1 in Supporting Information File 1) of the molecules also decrease (Figure 4). Conclusion In summary, the key step of regioselective double oxidative photocyclization was successfully employed in the preparation of three S-shaped double helicenes, namely, DH-1, DH-2 and DH-3 with (TMS

Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles

• Shao-Cong Zhan,
• Ren-Jie Fang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80

• provide great potential for applications in organic synthesis, pharmaceutical chemistry and materials science. Experimental 1. General procedure for the preparation of the spiro[carbazole-3,3'-inolines] 1a–j and 1a’–j’: A mixture of 2-methyl-1H-indole (0.5 mmol, 1.0 equiv), aldehyde (0.6 mmol, 1.2 equiv

• procedure for the preparation of the spiro[carbazole-2,3'-indolines] 2a–g and 2a’–g’: A mixture of 2-methyl-1H-indole (0.5 mmol, 1.0 equiv), aldehyde (0.6 mmol, 1.2 equiv), 2-(1-benzyl-2-oxoindolin-3-ylidene)malononitrile (0.5 mmol, 1.0 equiv) and CuSO4 (0.1 mmol, 0.2 equiv) in dry toluene (6.0 mL) was

• , 29.1; IR(KBr) υ: 3355, 3207, 3117, 3048, 2963, 2831, 2167, 1871, 1641, 1633, 1554, 1431, 1370, 1240, 1131, 1100, 972, 961, 881, 764 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C34H24N4O, 527.1842; found, 527.1849. 3. General procedure for the preparation of the tetrahydrospiro[carbazole-3,5'-pyrimidines

Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction

• Jan H. Griwatz,
• Anne Kunz and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2022, 18, 781–787, doi:10.3762/bjoc.18.78

• the preparation of large amounts of AB 1t (Scheme 2). This AB analogue was first synthesized by Masutani et al. in 2014 and was examined by them as well as in further studies by other groups regarding their potential for MOST applications, e.g., in a fluidic chip device by Wang et al. [1][26][27]. For

• . The solvent was recycled to minimize waste. After a total runtime of 3 days 72 g of AB 1t were obtained as pure red oil which corresponds to a yield of >99%. Therefore, the method should be suitable for the preparation of easily several 100 grams of azobenzene compounds. Conclusion In summary, the

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• , Germany 10.3762/bjoc.18.76 Abstract Continuous flow technology is a key technology for sustainable manufacturing with numerous applications for the synthesis of fine chemicals. In recent years, the preparation of odorants utilizing the advantages of flow reactors received growing attention. In this

• sustainable manufacturing [18]. Utilizing the virtue of flow chemistry, more and more methods for the preparation of odorants in flow are developed. Recently, Baxendale and co-workers reviewed techniques and apparatus tailored to the synthesis of flavors and fragrances [19]. In this review, we want to give an

• analyzed by GC, or, as demonstrated for the preparation of phenylethyl acetate, further diluted with ethyl acetate, and the biphasic system is separated in flow providing phenylethyl acetate in 82% isolated yield. Using this method, a variety of 2-phenylethyl-, cinnamyl-, geranyl-, n-hexyl-, and isoamyl

Complementarity of solution and solid state mechanochemical reaction conditions demonstrated by 1,2-debromination of tricyclic imides

• Petar Štrbac and
• Davor Margetić

Beilstein J. Org. Chem. 2022, 18, 746–753, doi:10.3762/bjoc.18.75

• , a synthetic methodology for the preparation of 1–3 was developed by Warrener and co-workers by a Zn/Ag couple debromination [13][14][15]. However, this methodology has some disadvantages, such as tedious preparation of the catalyst, the use of dry solvent and expensive silver acetate as well as side

• conditions (temperature) and the inability to control the elimination process [17]. The objective of this work was to establish whether the 1,2-debromination with the Zn/Ag couple could be carried out under solvent-free conditions in a ball mill and whether the tedious Zn/Ag couple preparation procedure [18

• usual procedure from Zn and silver acetate. Several simplifications of the Zn/Ag couple preparation were tested and showed that simple milling with Zn dust and Ag dust or wire can be also applied (Table 1, entries 5–8) [21]. Further improvement in the procedure was the replacement of the Ag dust with Cu

An isoxazole strategy for the synthesis of 4-oxo-1,4-dihydropyridine-3-carboxylates

• Timur O. Zanakhov,
• Ekaterina E. Galenko,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2022, 18, 738–745, doi:10.3762/bjoc.18.74

• Timur O. Zanakhov Ekaterina E. Galenko Mikhail S. Novikov Alexander F. Khlebnikov Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Naberezhnaya, St. Petersburg 199034, Russia 10.3762/bjoc.18.74 Abstract A method has been developed for the preparation of 2-alkyl-6

• , contain the fragment of 4-oxo-1,4-dihydropyridine-3-carboxamide [5][6][7]. Finding new synthetic methods for the preparation of derivatives of 4-oxo-1,4-dihydropyridine-3-carboxylic acid are therefore relevant. Some alkyl 6-aryl-2-methyl-4-oxo-1,4-dihydropyridine-3-carboxylates were prepared by refluxing

• a xylene solution of methyl/ethyl 3-aminobut-2-enoates and methyl/ethyl 3-aryl-3-oxopropanoates in the presence of molecular sieves, with methyl 3-aryl-3-oxopropanoates giving higher product yields (37–46%) than ethyl derivatives (13–25%) (Scheme 1) [13]. General methods for the preparation of 2,6

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• synthetic pathways usually involve employing strong conditions and toxic reagents. The current paper intends to provide a conceptually innovative synthetic protocol for mechanochemical isocyanide preparation, simultaneously lowering the related reagents' toxicity and improving their purification in a

• , for the aromatic starting compounds 1a–e, the reaction did not exceed the maximum of 82% yield obtained for 2e. It should be emphasized that the preparation of aromatic isocyanides has always been a challenging process from a synthetic point of view. Such a different fashion can be ascribed to the

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• in pET28 vector (BioCAT GmbH) and transformed into E. coli BL21 for heterologous expression. Additionally, a modified ubiA-297(R145A) gene was synthesized and cloned into a pET28 vector (BioCAT GmbH) yielding pET28-297(R145A) for heterologous expression. Preparation of enzyme extracts and protein

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• conventional heating methods, coupled with shorter cycle and start-up times. Rebrov et al. also suggested that the system can be used during periods of low power consumption to reduce the load on the electrical system. 2.5 Preparation of hydrocarbons (the Fischer–Tropsch process) Monodisperse Fe@FeCo core

• fixed-bed materials serving as catalysts: A. with copper metal, B. with Au-doped MagSilicaTM, and C. with Pd-doped MagSilicaTM. Two step flow protocol for the preparation of 1,1'-diarylalkanes 77 from ketones and aldehydes 74, respectively, and boronic acids 76. O-Alkylation, the last step in the

Mechanochemical halogenation of unsymmetrically substituted azobenzenes

• Dajana Barišić,
• Mario Pajić,
• Ivan Halasz,
• Darko Babić and
• Manda Ćurić

Beilstein J. Org. Chem. 2022, 18, 680–687, doi:10.3762/bjoc.18.69

• ; N-halosuccinimide; palladium(II); Introduction Electrophilic aromatic substitution [1][2][3] and ligand-directed transition-metal-catalyzed reactions [4][5][6][7][8] are among the most widely used synthetic approaches for the preparation of halogenated arenes. They are important precursors in cross

• studied functional groups, and new methods for their preparation, especially by environmentally friendly protocols, are of great synthetic importance in organic chemistry [54]. The succinimide products L4-III and L5-III (Table 1, entries 11 and 12) were obtained within one and five hours in 39 and 38

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• advantages of using readily available substrates, simple operation, good yields, and molecular diversity, which enable it to find potential applications in heterocyclic and medicinal chemistry. Experimental 1. General procedure for the preparation of the spiro[cyclohexane-1,3'-indolines] 3a–w: In an

• procedure for the preparation of the spiro[cyclohexane-1,3'-indolines] 5a–e: In an atmosphere of nitrogen, 3-(ethoxycarbonylmethyl)oxindole (0.5 mmol) and bis-chalcone (0.6 mmol) were dissolved in chloroform (10.0 mL) in a Schlenk bottle. Then, tri(n-butyl)phosphine (1.0 mmol) was added by syringe and the

• , 3412, 2933, 2871, 2324, 1925, 1817, 1703, 1604, 1474, 1442, 1339, 1172, 1091, 1010, 904, 824, 716 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C38H34ClNaNO4, 626.2069; found, 626.2066. 3. General procedure for the preparation of the spiro[cyclohexane-1,3'-indolines] 8a–m: In an atmosphere of nitrogen

New synthesis of a late-stage tetracyclic key intermediate of lumateperone

• Mátyás Milen,
• Bálint Nyulasi,
• Tamás Nagy,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2022, 18, 653–659, doi:10.3762/bjoc.18.66

• reduced with sodium cyanoborohydride in acetic acid to cis-indoline derivative (±)-35. Removal of the trifluoroacetyl group to (±)-36 followed by N-methylation with formaldehyde and sodium cyanoborohydride gave target compound (±)-9a. It has to be mentioned that the preparation of compound 31 has been

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• multicomponent ATP synthase motor [23], a more detailed and refined configuration of purposeful machinery [24]. For the preparation of heteroleptic aggregates, one must differentiate between dynamic (rapidly exchanging) and kinetically inert heteroleptic metal–ligand interactions. While the inert heteroleptic

• procedure developed by Sauvage on the basis of topological control [33] has found ample use in the preparation of rotaxane-based machines and devices [34]. A key element is a macrocyclic phenanthroline with an endotopic binding site as it precludes homoleptic complex formation. A further principle

• preparation of rotaxanes, the exploitation of cooperative and strain effects in double-click strategies is a promising strategy. A completely different approach to switchable supramolecular catalysis made use of a supramolecular cage-to-device transformation under dissipative conditions (Figure 24) [112

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• -phenylenediamine. The general method for the preparation of the corresponding quinoxalines on the basis of the aforementioned condensation was implemented. It was demonstrated that the studied photoreaction does not depend on the type of pyrazole bridge. The structures of three of synthesized products were

• in synthetic organic chemistry [1][2][3][4][5][6][7]. The advantage of photochemical methods is the possibility of the preparation of diverse products that are problematic to obtain using other chemical approaches. It should be noted that light can be considered as a traceless agent, therefore, UV

• subsequent opening leads to the final α-hydroxy-1,2-diketone 14a. Using the process conditions described above for the preparation of α-hydroxy-1,2-diketone 14a, we attempted to apply the elaborated method to the synthesis of a number of similar compounds with various substituents. Indeed, the proposed

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• heparinus and the aldolase from Escherichia coli K12 were produced in E. coli BL21(DE3). Both enzymes were purified and immobilized on different carriers to find for each enzyme the best choice for a stable and active enzyme preparation when applied under high pressure in continuous operation. For screening

• experiments. Furthermore, the most suited carrier with immobilized enzyme was analyzed in long-term studies with respect to the stability of the enzyme preparation. The enzymes were immobilized on six different carriers according to the instructions of the supplier (Lifetech Purolite, Ratingen, Germany). The

• well as the sample collection, and sample preparation for the analytics. For further analysis, long-term studies were carried out to analyze the stability in relation to different storage conditions such as the influence of moisture as well as temperature and mechanical stress. The stability of the

Synthesis of sulfur karrikin bioisosteres as potential neuroprotectives

• Martin Pošta,
• Václav Zima,
• Lenka Poštová Slavětínská,
• Marika Matoušová and
• Petr Beier

Beilstein J. Org. Chem. 2022, 18, 549–554, doi:10.3762/bjoc.18.57

• ) (Scheme 2) and provided the target compounds in good to high yields. Synthesis of KAR analogues with sulfur in position 6 Two different synthetic approaches were used for the preparation of C6 sulfur bioisosteres bearing a thiopyran moiety. For the synthesis of KAR1, KAR3 and KAR4 analogues, we proposed a

• (LiHMDS), followed by the addition of an alkyl halide. Application of this method to 8 provided the target molecule 21 in good yield (Scheme 4). It has to be mentioned that the metalation proceeds exclusively at C7, and thus cannot be used for the preparation of 20 via alkylation at C5. Our attempt to

• Goddard-Borger [24] for the preparation of 2 using the Xavier’s procedure [33] towards 5-thiopyranose-fused butenolides and the reaction pathway is outlined in Scheme 5. The synthesis of the key intermediate butenolide 23 was accomplished starting from easily available ᴅ-xylose, following a published

Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• method for the preparation of this class of compounds [2] and showed that DAS can undergo Rh(II)-catalyzed insertion reactions into the heteroatom–H bonds [3]. In 2020, it was shown that under Rh(II) catalysis, DAS can enter insertion reactions into the C–O bond of ethers [4], a rare transformation for

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• % yields. It is worth noting that common dilute conditions for macrocyclization reactions was not required here. Due to the very high efficiency, gram-scale preparation of the chiral macrocycles was readily achieved (see Supporting Information File 1). To enrich the diversity of the macrocyclic scaffolds

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• -1,2-diol, etc.) [11]. Beside this, approaches in which asymmetric synthesis is included are also applicable. Recently, the utilization of an asymmetric Henry reaction for the preparation of two oxazolidine-type drugs, namely linezolid (1) and rivaroxaban (2), has been described [12][13]. These

• published papers confirmed that the application of the asymmetric Henry reaction represents a promising alternative route for the feasible production of these compounds. Nevertheless, the studies provided only preliminary results, because they included only one enantioselective catalyst in the preparation

• of rivaroxaban (1) [12] and the study of the linezolid (2) synthesis used only commercially unavailable and poorly enantioselective catalysts (max 72% ee) [13]. In this paper, we focused on the application of the asymmetric Henry reaction for the preparation of the oxazolidine-2-one-type drugs

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

• -phenoxyketones, the most common methodologies are base-catalyzed alkylation of the corresponding phenols with halo- [28][29][30] and mesyl [31][32][33] ketones (Scheme 9), the preparation of which are not always selective and high-yielded. The ring opening of ArOCH2-epoxides [34][35], the SmI2-catalyzed

• reductive coupling of acid halides with ketones [36][37] and acetolyses of α-phenoxy-α-diazoketones [38] were also employed. Recently, F. P. Cossío et al. [39] have described a method for the preparation of benzo[b]furans by thermal heating of a dispersion of α-phenoxyketones in Al2O3. We involved the

• ) NMR techniques, as well as IR spectra. Typical procedure for preparation of phenoxyhydroxyketones 4 in DMF, 50–55 °C. To a stirred solution of Cs2CO3 (326 mg, 1 mmol) and phenol (2a; 94 mg, 1 mmol) in DMF (5 mL) 4-bromo-2-methylbut-3-yn-2-ol (1a; 196 mg, 1.2 mmol) was added dropwise. The reaction

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• . Review Preparation methods of menadione Among the most common methods for the preparation of menadione (10), we can find, for example, the oxidation of 2-methylnaphthalene or 2-methylnaphthol. Other less frequent but equally efficient approaches to synthesize menadione include the demethylation of 2

• nucleus, due to its greater reactivity when compared to the adjacent aromatic ring, which depends on previous modifications in the menadione intermediates [95]. Epoxidation reactions The use of menadione in the preparation of epoxides is widely reported in the scientific literature. In nature, menadione

• strategy applying Lewis acids can be used. Among the options, bismuth triflate is a catalyst, with the additional advantages of low-cost and easy preparation from commercially available bismuth oxide and triflic acid. Quinone acylation reactions took place under mild conditions using acetic anhydride and 2

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• : citronellal (75 mM), [16] (7.5 mM), Bu4NBr (3, 78 mM); E: citronellal (75 mM), acetic acid (29 mM); F: citronellal (75 mM), n-hexylresorcinol (2, 30 mM); G: citronellal (75 mM), [16·8H2O] (7.5 mM). Spectra recorded after 24 h at 60 °C, while A and B were recorder right after sample preparation. 1H NMR spectra

• , 30 mM); G: 1,1-diphenylethanol (75 mM), [16·8H2O] (7.5 mM). Spectra recorded after 3 h at 60 °C, while A and B were recorder right after sample preparation. 1H NMR spectra in water-saturated CDCl3 except for G. A: [16] (7.5 mM); B: α-pinene; C: α-pinene (75 mM), [16] (7.5 mM); D: α-pinene (75 mM

• ), [16] (7.5 mM), Bu4NBr (3, 78 mM); E: α-pinene (75 mM), acetic acid (29 mM); F: α-pinene (75 mM), n-hexylresorcinol (2, 30 mM); G: α-pinene (75 mM), [16·8H2O] (7.5 mM). Spectra recorded after 24 h at 60 °C, while A and B were recorder right after sample preparation. 1H NMR spectra in water-saturated

New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence

• Long Zhao,
• Mao-Lin Yang,
• Min Liu and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2022, 18, 286–292, doi:10.3762/bjoc.18.32

• biological activities, including anticancer [9], neuroprotective [10], antiproliferative and antifungal activities [11]. Due to the significant bioactive properties of the 3,4-dihydroquinazoline and 4H-3,1-benzothiazine moieties, many preparation procedures have appeared in the literature for the synthesis

• from aldehydes, a carboxylic acid, and a isonitrile as the three components [23]. The sequences of Passerini reactions, followed by post-condensation reactions, constitute useful synthetic methods in the preparation of structurally diverse heterocyclic compounds [24][25][26][27][28][29]. The aza-Wittig

• reaction has also been utilized widely in preparation of various heterocycles under mild neutral conditions [30][31][32]. Recently we have reported the synthesis of 3H-2-benzoxepin-1-ones, 4H-3,1-benzoxazines and oxazoles by combination of a Passerini with an intramolecular aza-Wittig reaction [33][34][35

Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity

• Anna V. Korotina,
• Svetlana G. Tolshchina,
• Rashida I. Ishmetova,
• Natalya P. Evstigneeva,
• Natalya A. Gerasimova,
• Natalya V. Zilberberg,
• Nikolay V. Kungurov,
• Gennady L. Rusinov,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2022, 18, 243–250, doi:10.3762/bjoc.18.29

• carried out for the first time. The synthetic approach to new triazolotetrazines involves the preparation of 3,6-disubstituted 1,2,4,5-tetrazines 2a–i bearing the amidine moiety through nucleophilic substitution of the 3,5-dimethylpyrazol fragment in easily available compound 1, followed by oxidative

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

• proven useful for the structural characterization of crystalline organic solids and which requires minimal sample preparation [29]. Pleasingly, analysis of the milled mixture (1c + NFSI) by PXRD evidenced the existence of diffraction reflections corresponding to crystalline (PhSO2)2NH, (PhSO2)2NCH3, and