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

• the cyclic hemiacetal 9 in modest yield (Scheme 2). Therefore, compound 8 was protected as silyl or benzyl ether using standard techniques. Unfortunately, no hydrolysis under several basic conditions provides the target ketone, no conversion and/or decomposition being observed (Scheme 3). Enol

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

• –97%). This method allows for easy recovery of the unreacted aldehyde as well as separation of the product (just by extraction by hexane and drying under reduced pressure) without its decomposition. The structure of the final imines was confirmed by 1H NMR, 13C NMR, ESI–MS, and the release of the VOCs

• bond decomposition that Shiff base hydrolysis is very fast in acidic conditions and slows down when going to higher pH values. Multiple headspace extraction experiments revealed the role of pH and the presence of supramolecular interaction between aldehyde and β-CD on the rate of aldehyde release from

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

• under the same reaction conditions led predominantly to decomposition products and only 5-methylfurfural (resulting from protodesilylation) was recovered in low yield (≈20%). Hence, intramolecular hydroxy activation seems decisive to obtain productive cross-coupling reactions with this system. Also, it

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

• diethyl ether at 0 °C for 1 h gave acid 10aa in 75% yield, while complete decomposition was observed at reflux temperature after only 10 min (Table 1, entries 1 and 2). Acid 10aa did not form when the reaction was performed in ethanol, CH2Cl2, THF, DMF, or ethyl acetate at different temperatures under

• formed in 50% yield in ethanol and 30% in diethyl ether (Table 1, entries 10 and 11). Reactions with thiol 8c, having an electron-donating methoxy group, and acid 9a or esters 9b,c only gave unidentifiable decomposition products in various solvents (ethanol, diethyl ether, methanol, and CH2Cl2) at

• (see Supporting Information File 1 for detailed reaction conditions) since decomposition of the benzothiazine core was observed in all coupling reactions. To avoid the issues related to the instable benzothiazine ring, we explored other possible linear reaction routes (Scheme 4) as an alternative to

Electro-conversion of cumene into acetophenone using boron-doped diamond electrodes

• Mana Kitano,
• Tsuyoshi Saitoh,
• Shigeru Nishiyama,
• Yasuaki Einaga and
• Takashi Yamamoto

Beilstein J. Org. Chem. 2022, 18, 1154–1158, doi:10.3762/bjoc.18.119

• , entry 2). On the other hand, the isolated yield of 3 was decreased by the addition of H2O (Table 2, entries 3 and 4). This is probably because the addition of H2O promoted the generation of hydroxyl radicals, and a decomposition reaction became dominant. These results indicated that the oxygen source is

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• . Diarylcyclopentenones, characteristic constituents of mushrooms [23], were rarely discovered in Streptomyces species. These components exhibit redox activity and are involved in reducing ferric (Fe3+) in the Fenton-based biological decomposition of lignocellulose [24][25]. The biosynthetic pathway of p-terphenyl was

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

• . Moreover, when using an excess of a strong base, a low temperature would favor the occurrence of the iminoimide 7 whereas at a higher temperature, decomposition and the cyclization process giving isomer 4 would prevail. Conclusion This report describes some of the reaction parameters which orient and

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• cheap and abundant starting materials their use is fraught with technical complications. This family of molecules is extremely sensitive to bench conditions and requires a carefully controlled refrigeration in addition to low light levels to avoid decomposition. Furthermore, true to the unique

• obtain the corresponding sulfinate in limited yield, the decomposition of this compound after several days at 4 °C, and within a few minutes under heating deemed its applicability impractical. After this first step, we proceeded to test the nucleophilic substitution between our perfluoroalkylsulfinate

• secondary carbon atom at 40 °C (Scheme 2). Furthermore, increasing the temperature to 70 °C was not found to generate the product and instead resulted in slight decomposition of the starting materials. Attempting to trap the sulfinate nucleophiles with primary benzyl bromide (4) with catalytic sodium iodide

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• prepared carbon tetrachloride solution of 1-chloro-2-phenylcyclopropene (2m) was treated with PRP (1) in THF medium. To avoid cyclopropene decomposition, the reaction was carried out at room temperature with stirring. Twelve hours later, we were pleased to note that azomethine ylide 1 was fully consumed as

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

• employed Stewart–Grubbs catalyst 71 is completely decomposed but its decomposition products could efficiently be removed by passing the reaction mixture through a cartridge containing a mixture of silica and charcoal providing 72 in 32% yield at a productivity of 0.2 g/h. The macrocycle 72 was already

• -closing metathesis reaction for the preparation of macrocyclic musks, the efficient removal of ethylene by the means of a tube-in-tube reactor or a continuously stirred tank reactor (CSTR) can promote the reaction and suppress decomposition of the catalyst. In addition, reactions involving organometallics

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

• pressure, much higher temperatures around 950 °C are actually required. At these high temperatures, the selectivity of the process is a challenge. Possible side reactions such as hydrogenation of CO and CO2, decomposition of CH4, and the Boudouard reaction lead to the formation of elemental carbon [31

• 180 °C at 4.5 MPa for 7.5 min. These conditions allowed to suppress the decomposition of the N-alkylation product 78 by using a 1/8“-reactor. The subsequent purification was realized by a clever catch and release protocol based on a silica column, yielding iloperidone (80, 67%). The tricyclic

Rapid gas–liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

• Kyoko Mandai,
• Tetsuya Yamamoto,
• Hiroki Mandai and
• Aiichiro Nagaki

Beilstein J. Org. Chem. 2022, 18, 660–668, doi:10.3762/bjoc.18.67

• oxidation and decomposition of oxidants generated from air and aldehyde. Furthermore, the fast epoxidation is applicable for the continuous production process of cyclohexene oxide for 1 hour maintaining stable operation. Results and Discussion Batch experiment of epoxidation of cyclohexene with air As an

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

• 24 was accomplished in neat conditions within 3 days of reaction time using a literature procedure [5]. Attempts in acetonitrile as solvent were unsuccessful: after 1 day at room temperature, product 28 was isolated in only 20% yield, while at reflux temperature, a decomposition has been observed

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

• darkness at room temperature for 5 days resulted in complete decomposition. Despite the labile nature of α-hydroxy-1,2-diketone 14a we attempted to isolate this product in pure form. It should be noted that in contrast to the methylated derivative 16, pyrazole 12a has a low solubility in most organic

• medium accelerates the decomposition of target α-hydroxy-1,2-diketone 14a. Subsequently, we used DMF as a solvent for carrying out the studied photoreaction. Unexpectedly, the starting pyrazole 12a was isolated unchanged after 24 hours of UV irradiation, indicating that DMF also is not suitable for the

• were unsuccessful due to the low stability of the resulting α-hydroxy-1,2-diketone 14 and their partial decomposition during purification. Thus, the purity of the obtained compounds 14 does not allow a complete characterization by various analytical methods. Based on this fact we made attempts to

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

• Federal University, Kaliningrad 236041, Russian Federation 10.3762/bjoc.18.55 Abstract Formation of unusual unsymmetrical dimers or/and indenes via Rh2(esp)2-catalyzed decomposition of 3-diazo-2-arylidenesuccinimides has been investigated. The reaction proceeded under mild conditions, and its result was

• against the A549 human lung adenocarcinoma cell line while N-aryl analogs were non-cytotoxic. Keywords: diazo arylidene succinimides; dibenzoazulenodipyrroles; indenopyrroles; Rh2(esp)2-catalyzed decomposition; unsymmetrical dimers; Introduction 3-Diazo-2-arylidenesuccinimides 1 (DAS) are heterocyclic

• diazocarbonyl compounds [5]. The close spatial arrangement of the conjugate aryl fragment and the diazo group in the DAS molecule favors both intramolecular and intermolecular cyclizations involving the arylidene group. Thus, under catalytic decomposition, DAS containing a 2-pyridyl or 2-hydroxyaryl substituent

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

• -naphthoquinone (18) were obtained in 80% yield with a 75:25 ratio, respectively (Scheme 2, method A). In the methylation reaction using methyl radicals generated by the redox decomposition of H2O2 in DMSO solution, compounds 10 and 18 were obtained in an overall yield of 80–90% with a 77:23 ratio, respectively

• (Scheme 2, method B). Finally, the use of H2O2 thermal decomposition in acetone with catalytic methanesulfonic acid, led to compounds 10 and 18 in 47% yield with 86:14 ratio (Scheme 2, method C). In all cases, the monomethylation was not selective and even at partial conversions of naphthoquinone

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• all, as neither the reaction of 2a with NaIO4 and hydrochloric acid, nor the reaction of 2a with LiOH and subsequent addition of acid (ammonium chloride, hydrochloric acid) gave the desired boronic acid, but led to decomposition, instead. Obviously, the 2-borylated norbornadiene derivatives are acid

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• been reported before. The isolated metabolite 5 represents the previously described siderophore amamistatin B [7], while compound 6 was before only known as a decomposition product of a synthetically prepared obafluorin derivative [8]. Results and Discussion To induce siderophore biosynthesis in N

Synthesis of piperidine and pyrrolidine derivatives by electroreductive cyclization of imine with terminal dihaloalkanes in a flow microreactor

• Yuki Naito,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 350–359, doi:10.3762/bjoc.18.39

• electrodes and subjected to the electrolytic reaction. Tetrahydrofuran (THF), which is easily oxidized, was employed as the electrolytic solvent, so the reaction at the anode (counter electrode) is thought to be preferentially caused by the oxidative decomposition of THF, and the re-oxidation of the cathodic

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• this methodology to related substrates with free indolyl NH as such reactions resulted into a complex mixture (not shown here), possibly due to the decomposition of the substrates. Nevertheless, the same regioselectivity was observed when the FC-acylation of N-protected 3-(4-indolyl)propanoic acids 28g

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• in a slight decrease in yield, and an increase in decomposition was observed with an increase in temperature despite the short residence times (entries 6 and 7, Table 2). The lack of solubility of the hydrazone substrates limited options with regards to variation in reaction solvent, with adequate

• prove useful for accessing small quantities of medicinally interesting BCP-1,3,4-oxadiazole compounds for biological testing. Additionally, the reaction of 1,3-substituted isoxazole 1m under these conditions was investigated. Despite high degrees of decomposition, it was possible to isolate the desired

Chemoselective N-acylation of indoles using thioesters as acyl source

• Tianri Du,
• Xiangmu Wei,
• Honghong Xu,
• Xin Zhang,
• Ruiru Fang,
• Zheng Yuan,
• Zhi Liang and
• Yahui Li

Beilstein J. Org. Chem. 2022, 18, 89–94, doi:10.3762/bjoc.18.9

• , Scheme 3). The results indicate that this N-acylation reaction of indole has great potential in practical synthesis. Some control experiments were conducted to explore the reaction mechanism of this transformation (Scheme 4). When S-methyl decanethioate (2i) was adopted without Cs2CO3, no decomposition

A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones

• Yuki Yamamoto,
• Akihiro Tabuchi,
• Kazumi Hosono,
• Takanori Ochi,
• Kento Yamazaki,
• Shintaro Kodama,
• Akihiro Nomoto and
• Akiya Ogawa

Beilstein J. Org. Chem. 2021, 17, 2906–2914, doi:10.3762/bjoc.17.198

• in a dramatically lower yield of 3a (8%), most likely because 3a is unstable to base at room temperature and may decompose or polymerize (see Supporting Information File 1). To avoid decomposition or polymerization, 3a produced in situ by the intramolecular cyclization of 2a should be separated

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• transformations without decomposition [37][38][39]. In the herein presented study, we apply the cyclative cleavage reaction to pyrazolyltriazenes instead of aryltriazenes, which results in the synthesis of diverse pyrazolo[3,4-d][1,2,3]-3H-triazine derivatives 5. Results and Discussion According to the literature

• of the target compounds of class 5 were chosen as they were available in sufficient amounts and showed no decomposition during storage and dilution in DMSO. Also, most of the intermediates showed no reduction of cell viability; however, compounds 9b, 12b,c, 13a,b, and 13f–h showed some cytotoxic

Ligand-dependent stereoselective Suzuki–Miyaura cross-coupling reactions of β-enamido triflates

• Tomáš Chvojka,
• Athanasios Markos,
• Svatava Voltrová,
• Radek Pohl and
• Petr Beier

Beilstein J. Org. Chem. 2021, 17, 2657–2662, doi:10.3762/bjoc.17.179

• study. Substituted phenylboronic acids and vinyl triflates led to the formation of enamides 2 with high stereoselectivity and in good to high NMR yields (Scheme 2). However, isolated yields were found to be lower due to the decomposition of the formed enamides 2 during column chromatography on silica

• -trifluoromethylphenyl group which gave enamides 3da (2da/3da, 20:80) and 3dd (2dd/3dd, <1:99). It is worth mentioning that the reaction of vinyl triflate 1c with 3-methoxyphenylboronic acid led to full decomposition of the starting material. The stereochemistry of the double bond in compounds 2 and 3 was determined by