Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• amount of pyrrole is presented for the first time. This procedure is a simple and efficient way for the preparation of corroles with a polymerizable substituent on meso-positions. Keywords: corrole; dipyrromethane; macrocycles; metal triflates; pyrrole; Introduction Corroles, a member of contracted

Preparation of an advanced intermediate for the synthesis of leustroducsins and phoslactomycins by heterocycloaddition

• Anaïs Rousseau,
• Guillaume Vincent and
• Cyrille Kouklovsky

Beilstein J. Org. Chem. 2022, 18, 1385–1395, doi:10.3762/bjoc.18.143

• preparation and the coupling of three main fragments (Figure 2): the lactone fragment 3, the central fragment 4 and the cyclohexane fragment 5. We have previously described the enantioselective synthesis of the lactone fragment 3 [18]; we now disclose the synthesis of the oxazinone 4 and attempts for coupling

• completion of the total synthesis via the preparation and coupling of the fragment 5 is under study in our laboratory. Experimental Unless otherwise stated, all reactions were conducted in oven-dried glassware under an atmosphere of dry argon. Tetrahydrofuran was distilled over sodium/benzophenone ketyl

On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

• hits to human/mammalian pharmacology are comparatively and inherently very-very slow. The time needed for the preparation of a handful of analogues of a hit will depend on the chemistry and the number of synthetic steps required. When the chemistry is neither known nor easy, this can take up to months

• blog [110] is worth reading in full. Moreover, applying too much pressure on the chemists to produce these analogues, or subcontracting the whole process, is likely to orient the synthetic work toward the preparation of “easy” compounds. The inherent risk then being to miss the initially hard to get

• [263][264][265][266][267][268][269][270][271]. Years after their preparation, this strategy led to tools of biological interest once [102][103] and all of them remain in chemical libraries, just waiting to be assayed in a “right” screening. To pursue this approach, the first step could be to

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• ), Dunkerque, France 10.3762/bjoc.18.140 Abstract A simple method for the preparation of β-cyclodextrin derivatives containing covalently bonded aldehydes via an imine bond was developed and used to prepare a series of derivatives from 6I-amino-6I-deoxy-β-cyclodextrin and the following volatile aldehydes

• , in all cases, a large excess of an aldehyde. Finally, the best reaction conditions for the large-scale preparation of target compounds proved to be just refluxing of amine 1 with up to 30-fold excess of the aldehydes 2a–j in methanol (Scheme 1), which afforded the final imines 3a–j in high yields (80

• method for their preparation was developed – Shiff base pro-fragrance is formed by refluxing amino-β-CD with an excess of a volatile aldehyde in methanol and purified just by extraction. The use of CD is interesting as it acts as a double barrier carrier for fragrance aldehyde molecules. We illustrated

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• transition metal-catalyzed cross-coupling reactions broadly used for the preparation of different diarylacetylenes and, rarely, bis(chlorophenyl)acetylenes. Next, starting substituted benzaldehydes were treated with an excess of SOCl2 for 24 h at 25 °C. Corresponding substituted benzal chlorides 4 were

• backbone. Recently, we have reported a convenient method for the preparation of 1,2-diphosphaferrocenes [37] and 1,2,3-triphosphaferrocenes [25] with various substituents at para-positions of aryl groups. Using this approach, sodium bis(diglyme) 3,4,5-tris(3-chlorophenyl)-1,2-diphosphacyclopentadienide (7b

• -substituted benzaldehydes. We found that the reaction of tributyl(1,2,3-tris(chlorophenyl)cyclopropenyl)phosphonium bromides 6 with sodium polyphosphides can be successfully used for the preparation of sodium 3,4,5-tris(chlorophenyl)-1,2-diphosphacyclopentadienides 7. A facile synthesis of 3,4,5-tris(3

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• likely is the most pragmatic and straightforward preparation of the enzymes for their use in chemical synthesis. The assay setup used for all PPKs is similar to established ATP regeneration systems with PPK2 enzymes, with a 10:1 excess of polyP (calculated as single phosphates [49]) over the nucleotide

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• cyclization is a simple and efficient strategy for the preparation of the 2,5-dihydrofuran moiety present in many natural products. In fact, we have achieved the total synthesis of the 2,5-dihydrofuran structure 1. After systematic data analysis of our prepared compound and those in the literature, it can be

Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization

• Sebastien Curpanen,
• Per Reichert,
• Gabriele Lupidi,
• Giovanni Poli,
• Julie Oble and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131

• reagents [22][23] to these substrates was uneventful and allowed for the preparation of 2-furylalkyl (see 3a–c, 4c), -aryl (see 5c, 6c), and -allyl carbinols (see 7c) having furan rings with various triorganosilyl substituents at C3 in a synthetically useful yield and on an appropriate scale (Scheme 2

• details). We also contemplated the use of alkyl iodides as electrophiles. Methylation with methyl iodide was efficient, as shown through the preparation of 28 in 61% yield from 4c. In contrast, higher alkyl iodides, such as ethyl iodide, failed to provide the alkylation product (i.e., 29) and only

• building blocks. Experimental Procedure for the addition of n-BuLi to C3-silylated furfurals (preparation of compounds 3a–c and 4c) In a flame-dried round-bottom flask under argon was placed the appropriate C3-silylated furfural [15] and dissolved in freshly distilled THF (0.3 M). The solution was cooled

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

• and Life, Beijing University of Technology, Beijing 100124, China 10.3762/bjoc.18.130 Abstract The electrochemical preparation of 2-aminothiazoles has been achieved by the reaction of active methylene ketones with thioureas assisted by ᴅʟ-alanine using NH4I as a redox mediator. The electrochemical

• pharmaceutical activities such as antimicrobial [2][3], antiviral [4], antitumor [5][6], anti-inflammatory [7][8] and so on. Moreover, as a type of important intermediates, thiazole is of prime importance in organic synthesis [9][10] which is used extensively in the preparation of flavors [11], polymers [12

From amines to (form)amides: a simple and successful mechanochemical approach

• Federico Casti,
• Rita Mocci and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 1210–1216, doi:10.3762/bjoc.18.126

• mechanochemical conditions are presented. The two methodologies exhibit complementary features as they enable the derivatization of aliphatic and aromatic amines. Keywords: acetamides; formamides; mechanochemistry; N-formylation; p-tosylimidazole; Introduction The preparation of N-formylated and N-acetylated

Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates

• Péter Kisszékelyi,
• Tibor Peňaška,
• Klára Stankovianska,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124

• , antifungal, antiviral, antimalarial, antidiabetic, antihypertensive, anti-inflammatory, analgesic, anti-rheumatic, or anti-allergic properties [1][2][3][4][5]. Several methods for the preparation of 4H-benzo-1,4-thiazines have been described in the literature. Methods for the synthesis of 2,3-disubstituted

• , three-component procedure was also explored for the preparation of 3-aryl-4H-benzo-1,4-thiazin-2-amines [18]. 3-Aryl- and 3-alkyl-4H-benzo[b][1,4]thiazine-4-carbonitriles 2 (Figure 1) were synthesized in high yield from the corresponding 2-aminobenzothiazoles using the copper–organic framework Cu–MOF-74

• transform into a green-blue chromophore in the presence of peroxides or redox-active metal ions under acidic conditions, creating a potential detection method for such entities [29]. Additionally, the same structure was used for the preparation of a benzo-1,4-thiazine-based cyanine chromophore, which showed

Synthesis of protected precursors of chitin oligosaccharides by electrochemical polyglycosylation of thioglycosides

• Md Azadur Rahman,
• Kana Kuroda,
• Hirofumi Endo,
• Norihiko Sasaki,
• Tomoaki Hamada,
• Hiraku Sakai and
• Toshiki Nokami

Beilstein J. Org. Chem. 2022, 18, 1133–1139, doi:10.3762/bjoc.18.117

• polyglycosylation via the electrochemical activation of thioglycosides is a practical approach for the preparation of chitin oligosaccharides. Hashimoto and co-workers have already reported the synthesis of protected precursors of chitin oligosaccharides by polyglycosylation of thioglycosides [5]. However, this is

Electrogenerated base-promoted cyclopropanation using alkyl 2-chloroacetates

• Kouichi Matsumoto,
• Yuta Hayashi,
• Kengo Hamasaki,
• Mizuki Matsuse,
• Hiyono Suzuki,
• Keiji Nishiwaki and
• Norihito Kawashita

Beilstein J. Org. Chem. 2022, 18, 1116–1122, doi:10.3762/bjoc.18.114

• method is one of the most environmentally benign and accessible methods for the preparation of 1,2,3-trisubstituted cyclopropane derivatives, notwithstanding the low reaction yields. In our laboratory, further synthetic investigations are in progress. Formations of 1,2,3-trialkyl

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• acquired under N2 gas by a Chirascan V100 spectrometer (Applied Photophysics). Strain cultivation was performed at 28 °C in an incubator for agar plates or in a rotary shaker at 200 rpm for liquid media. Strain preparation and fermentation The strain S. cattleya NRRL 8057 was purchased from the China

Synthesis of N-phenyl- and N-thiazolyl-1H-indazoles by copper-catalyzed intramolecular N-arylation of ortho-chlorinated arylhydrazones

• Yara Cristina Marchioro Barbosa,
• Guilherme Caneppele Paveglio,
• Claudio Martin Pereira de Pereira,
• Sidnei Moura,
• Cristiane Storck Schwalm,
• Gleison Antonio Casagrande and
• Lucas Pizzuti

Beilstein J. Org. Chem. 2022, 18, 1079–1087, doi:10.3762/bjoc.18.110

• . Despite the lower yield, this is the first reported method for the preparation of such compounds. In summary, N-phenyl- and N-thiazolyl-1H-indazoles were conveniently obtained from the less expensive and more available o-chlorinated arylhydrazones. Experimental General All chemicals were purchased from

Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold

• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109

• ] (Figure 1). The privileged 1,4-DHIQs would be a highly suitable platform for a stereodefined presentation of three different diversity vectors of the lactam moiety. However, the methods for the preparation of 1,4-DHIQs with convenient and independent variation of the three lactam substituents are absent

• homophthalimides 8 [10][11][12]. We reasoned that a similar strategy could be adopted for the preparation of 1,2,4-trisubstituted 1,4-DHIQs 9 if access to their diazo precursors 10 was gained. N-Sulfonyl analogs of compounds 10 have recently been synthesized via an innovative Dimroth rearrangement of 4

• -diazoisochroman-3-imines [13] and employed in several acid- and metal-promoted transformations by Lu, Wang et al. [14][15][16][17][18]. However, preparation of precursor 10 by direct diazo transfer onto the methylene group of readily available [19][20] 3(2H)-isoquinolones 11 has not been described in the

Electrochemical Friedel–Crafts-type amidomethylation of arenes by a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborate

• Hisanori Senboku,
• Mizuki Hayama and
• Hidetoshi Matsuno

Beilstein J. Org. Chem. 2022, 18, 1040–1046, doi:10.3762/bjoc.18.105

• the proton source in electrochemical amidomethylation. Effect of trialkylammonium salt in electrochemical amidomethylation. Screening of reaction conditions in electrochemical amidomethylation. Supporting Information Supporting Information File 84: General experimental information, preparation of

A versatile way for the synthesis of monomethylamines by reduction of N-substituted carbonylimidazoles with the NaBH₄/I₂ system

• Lin Chen,
• Xuan Zhou,
• Zhiyong Chen,
• Changxu Wang,
• Shunjie Wang and
• Hanbing Teng

Beilstein J. Org. Chem. 2022, 18, 1032–1039, doi:10.3762/bjoc.18.104

• chemicals, agrochemicals, pharmaceuticals and dyes [1][2][3][4]. Traditional methods for the preparation of N-methylamines involve the direct methylation of amines by using methyl halides [5][6][7], dimethyl sulfate [8], diazomethane [9], methyl triflate [10][11] or dimethyl carbonate [12][13][14][15] as

• method is to introduce alkyl formate, formacyl, methylene or their equivalents to amines, followed by reduction to give monomethylamines [44][45][46][47][48][49][50][51]. Protection/methylation/deprotection strategies have also been developed for the preparation of monomethylation objects, which are

• conditions are not significantly changed compared to our previous preparation of formamide. With this reduction system, we achieved a one-step conversion from N-substituted carbonylimidazoles to methylamines. This interesting work will help to synthesize pure monomethylamines from a wide range of raw

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• of α-arylvinyl acetates to access diverse vicinal α-azidoketones. The protocol employs the experimentally simple undivided electrochemical cell and tolerates a broad substrate scope. The obtained α-azidoketones have been shown to be versatile building blocks for the preparation of biologically

Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

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

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• chemistry. Experimental 1. General procedure for the preparation of functionalized cyclopent-2-enes 3a–l: To a round-bottomed flask was added phenacylmalononitrile (0.5 mmol), dialkyl but-2-ynedioate (0.6 mmol), tetrabutylammonium bromide (0.25 mmol), and acetonitrile (5.0 mL). The solution was stirred at

• , 391.1271. 2. General procedure for the preparation of functionalized carboxamide-bridged dicyclopentenes 4a–k: To a round-bottomed flask was added phenacylmalononitrile (0.5 mmol), dialkyl but-2-ynedioate (0.6 mmol), DABCO (1.0 mmol), and acetonitrile (5.0 mL). The solution was stirred at room temperature

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• . Jones disclosed an original synthesis of 2-hydroxypyrazines involving a double condensation between 1,2-dicarbonyls and α-aminoamides upon treatment with sodium hydroxide at low temperature. This discovery turned out to be of importance as even today there are no simple alternatives to this preparation

• , this has never been the subject of a report. Our recent interest in the preparation of 3,5-substituted-2-hydroxypyrazines (3, R2 = Ar and R3 = CH2Ar) as intermediates for the synthesis of marine luciferins analogues [29][30] along with the simplicity of this access drove us to study some of its aspects

• which led to the improvements and insights described in the following. Results and Discussion The preparation of 3,5-substituted-2-hydroxypyrazines 3 is usually undertaken [6][13][18][19][20][21][22][23][25][26][27][28][31] as follows. The α-ketoaldehyde 1 and the hydrochloride salt of the α-aminoamide

Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products

• Nisha Devi and
• Virender Singh

Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92

• spectra were recorded after 15 minutes of sample preparation in 5 × 10−6 M concentration and fluorescence intensity was observed to be in the following order: CHCl3 > EtOAc > CH2Cl2 > DMF. The results of the optimization studies are presented in Figure 5 and it was concluded from the studies that C-3

• -substituted pyrido[3,4-b]indole derivative 7dA displayed the maximum fluorescence intensity in chloroform at a concentration of 5 × 10−6 M after 15 minutes of sample preparation. Accordingly, fluorescence studies of all the other derivatives were conducted following these optimized parameters, i.e., time: 15

• × 10−6 M in chloroform solvent after 15 minutes of sample preparation. Derivatives 7cB and 7cE bearing an o-bromophenyl substituent at R1 position emerged as two most fluorescent compounds in the present series. Furthermore, products of type 7 (Morita–Baylis–Hilman adducts) were more fluorescent than

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• the preparation of 1,2-azaphospholidine and 1,2-azaphospholine 2-oxide derivatives. Synthesis of 1-phenyl-2-phenylamino-γ-phosphonolactam (2) from N,N’-diphenyl 3-chloropropylphosphondiamide (1). Synthesis of 2-ethoxy-1-methyl-γ-phosphonolactam (6) from ethyl N-methyl-(3-bromopropyl)phosphonamidate (5

Efficient production of clerodane and ent-kaurane diterpenes through truncated artificial pathways in Escherichia coli

• Fang-Ru Li,
• Xiaoxu Lin,
• Qian Yang,
• Ning-Hua Tan and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2022, 18, 881–888, doi:10.3762/bjoc.18.89

• chemoenzymatic strategies and biocatalysis in preparation of high value diterpenoid natural products. (a) The natural pathways (MVA: blue, MEP: green) for producing IPP and DMAPP; (b) the carbon skeletons of clerodane and kaurane diterpenes and representative bioactive natural products. acetoacetyl-CoA thiolase

Palladium-catalyzed solid-state borylation of aryl halides using mechanochemistry

• Koji Kubota,
• Emiru Baba,
• Tamae Seo,
• Tatsuo Ishiyama and
• Hajime Ito

Beilstein J. Org. Chem. 2022, 18, 855–862, doi:10.3762/bjoc.18.86

• mill; borylation; cross-coupling; mechanochemistry; solid-state reaction; Introduction Arylboronic acid and its derivatives are indispensable reagents in modern synthetic chemistry because they have been frequently used for the preparation of many bioactive molecules, natural products, and functional