Organophosphorus chemistry: from model to application

• György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

• in organophosphorus chemistry. A series of P-stereogenic chiral thiophosphorus acids, such as a fused 1-hydroxytetrahydrophosphinine 1-sulfide, an oxaphosphinine sulfide analogue, and an azaphosphinine sulfide analogue were synthesized my Montchamp and Winters as potential organocatalysts [4]. The

Total synthesis of grayanane natural products

• Nicolas Fay,
• Rémi Blieck,
• Cyrille Kouklovsky and
• Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

• ]octane CD ring system with the correct configuration. The synthesis started from commercially available (S)-2-((p-toluenesulfonyl)oxy)-1-propanol (6) which was converted to (R)-2-(benzyloxy)propionaldehyde (7) by a sequence involving formation of the a phenyl sulfide through an epoxide intermediate

• the formation of 15. This intermediate was coupled with an (R)-epoxide in presence of s-BuLi, and intermediate 16 with E configuration was then obtained by a (PhS)2-accelerated 1,3-sulfide shift. The A ring was then cyclized by a sequence consisting of protection of the alcohol, oxidative cleavage of

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• electrophile and the nucleophile with the specific preorganization of the substrates by the catalyst is crucial for high enantioselectivity [67] (as in example A in Scheme 4). However, in example B the transition state without specific interactions between the sulfide and the catalyst is proposed. In this case

• , the acidic and basic sites of the catalyst are suggested to be involved in the activation of only hydrogen peroxide within a well-defined and deep chiral cavity. The enantioselective approach of sulfide to H2O2 is ensured by the sterically demanding structure of the catalyst. It should also be noted

• that hydrogen bonding is considered as one of the key factors determining the selectivity of catalyst-free sulfoxidations [68]. In such reactions, the selectivity of sulfide oxidation by oxone (sulfoxide/sulfone ratio) was controlled by the solvent nature (deeper oxidation was observed in water than in

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• . Subsequent reduction with sodium dithionite then afforded triamine 9. Another way comprised the installation of a nitroso group in compound 6 through reaction with in situ-generated nitrous acid giving nitroso compound 8. The subsequent reduction to the corresponding amine with hydrogen sulfide afforded the

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

• for the synthesis of 1,2-azaphospholidine 2-oxides/sulfides and their fused derivatives. The 1,2-azaphospholidine 2-oxide/sulfide derivatives have been prepared by construction of any of their ring bonds. Synthesis via C–N bond formation In 1962, Helferich and Curtius reported the first synthesis of a

• -arylaminopropyl(methyl)phosphinic acids 45 under reduced pressure. The reactions of 1,2-oxaphospholane 2-oxides 47/2-sulfides 50 and anilines 48 generated 1-aryl-2-methyl-1,2-azaphospholidine 2-oxides 49 and 46a as well, while the reaction of 1,2-thiaphospholane 2-sulfide (51) with aniline (48a) gave

• azaphospholidine 2-sulfide 52 in only 21% yield by heating at 200 °C for 60 h (Scheme 8) [28]. In 1982, Collins and co-workers prepared both 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 56 and 2-sulfide 60 through heating zwitterionic 2-aminobenzyl(phenyl)phosphinic acid 54 and 2-aminobenzyl(phenyl

Cathodic generation of reactive (phenylthio)difluoromethyl species and its reactions: mechanistic aspects and synthetic applications

• Sadanobu Iwase,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2022, 18, 872–880, doi:10.3762/bjoc.18.88

• bromodifluoromethyl phenyl sulfide (1) using o-phthalonitrile as a mediator generated the (phenylthio)difluoromethyl radical, which reacted with α-methylstyrene and 1,1-diphenylethylene to provide the corresponding adducts in moderate and high yields, respectively. In contrast, chemical reduction of 1 with SmI2

• generation of (phenylthio)difluoromethyl reactive species from bromodifluoromethyl phenyl sulfide and their synthetic application as well as mechanistic aspects. Results and Discussion Cathodic reduction of bromodifluoromethyl phenyl sulfide (1) At first, the reduction potential (Epred) of

• bromodifluoromethyl phenyl sulfide (1) was measured by cyclic voltammetry in an anhydrous acetonitrile (MeCN) solution containing Bu4NClO4 (0.1 M) using a platinum electrode. One irreversible reduction peak was observed at −2.4 V vs SSCE at a scan rate of 100 mV/s. Even at a much higher scan rate of 500 mV/s, 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

• closure (Scheme 1). A plausible mechanism for the cyclization of compounds 7 is the Darzens reaction to episulfide, followed by Barton–Kellogg-type reaction with triphenylphosphine and elimination of triphenylphosphine sulfide. Compound 8 showed lower germination activity than KAR1 [22], but achieved IC50

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

• smoothly substituted at the α-position with benzenethiol (4) in the presence of K2CO3 to afford the unsymmetrically functionalized sulfide 5 in 86% yield; 5 is a precursor to some pharmaceutical cores (Scheme 4) [45][46][47][48]. However, α-bromo-δ-valerolactone (3a) was extremely unstable under ambient

• 2a. Synthesis of α-functionalized lactones using the two-phase system. Synthesis of unsymmetrically functionalized sulfide 5 via the two-phase system-promoted intramolecular cyclization of 2b. Sequential nucleophilic substitution in the two-phase system. One-pot synthesis of 2-phenylthio-α

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• derivative 17. This was obtained as a mixture of endo- and exo-sulfoxides. Esterification of 17 was carried out with dimethyl sulfate to give methyl ester 18, which was further reduced using dichloroborane and dimethyl sulfide to provide sulfide 19 in 80% yield in THF as solvent. Hydrolysis of compound 19

• condensation of the sodium salt of methyl 2-mercaptoacetate (3j) with bromoacetaldehyde diethyl acetal (36) in DMF solvent and further oxidation of the sulfide using m-CPBA, followed by Pummerer rearrangement using Ac2O and sodium acetate at 90 °C, which provides compound 37 (Scheme 9). α-Acetoxy sulfide

• intermediate 37 was resolved using a lipase in t-BuOMe, resulting in a high enantiomeric excess. They used an enzymatic resolution of an acetoxy sulfide with a Pseudomonas fluorescens lipase to obtain compound 38. Reaction of chiral acetoxy sulfide 38 with HCl in dry ethanol induced acetate removal by

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• , Stellenbosch University, Matieland 7602, Stellenbosch, South Africa 10.3762/bjoc.17.170 Abstract A wide range of N-(ethoxycarbonylmethyl)enaminones, prepared by the Eschenmoser sulfide contraction between N-(ethoxycarbonylmethyl)pyrrolidine-2-thione and various bromomethyl aryl and heteroaryl ketones

• described in this article. Results and Discussion The benzoyl-containing enaminone 15a (Ar = Ph) was selected as a model for investigating conditions for the cyclization. This compound was conveniently prepared by Eschenmoser sulfide contraction [29][30], as shown in Scheme 2. The route entailed initial

• bromide in acetonitrile at ambient temperature to produce the putative S-alkylated salt was complete within 18 hours, after which treatment with triethyl phosphite and triethylamine rapidly completed the sulfide contraction, giving (E)-enaminone 15a in 92% yield after chromatographic purification. The

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• catalytic and uncatalytic synthetic strategies adopted for the synthesis of the non-ionic (non-metallic) versions of these important molecules till date. Keywords: bisindole; heteroatom; indole; selenide; sulfide; Introduction Indole can be considered as a “prodigy” in the family of nitrogen-based

• Friedel–Crafts fashion (Scheme 10a) gave 82 with moderate to good product yields, respectively [69][70]. A similar work by Janosik involved strongly basic conditions at low temperature with bis(phenylsulfonyl)sulfide (83) as the sulfur donor (Scheme 10b) [73][74]. Disulfides are also important reagents

• for accessing bis(indolyl)sulfides. To synthesize the unsymmetrical bis(indolyl)sulfide 88, Janosik reacted the indole disulfide 87 with free indole and obtained the product 88 in 81% yield, where the sulfur linkages were 2,3’- with respect to the two indole nuclei (Scheme 11a) [73][74][75][76]. Hall

Total synthesis of ent-pavettamine

• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2021, 17, 1440–1446, doi:10.3762/bjoc.17.99

• yield. The first step involved esterification of malic acid using methanol, followed by selective reduction of the resulting dimethyl ester using borane dimethyl sulfide (BMS) yielding diol 5 (Scheme 2) [1][14][15]. The step achieved chemo-differentiation of the carboxyl groups present in 3 whilst

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• olefination of 4,4'-dimethoxybenzophenone with methoxy(trimethylsilyl)methyl p-tolyl sulfide, and oxidation of the resulting 1-methoxyvinyl p-tolyl sulfide with mCPBA (Scheme 3b) [17]. The 1-chlorovinyl p-tolyl sulfoxides 2e–g were prepared through a one-pot procedure (Scheme 3c) [15]. The HWE reagent was

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Synthesis of multiply fluorinated N-acetyl-D-glucosamine and D-galactosamine analogs via the corresponding deoxyfluorinated glucosazide and galactosazide phenyl thioglycosides

• Vojtěch Hamala,
• Lucie Červenková Šťastná,
• Martin Kurfiřt,
• Petra Cuřínová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2021, 17, 1086–1095, doi:10.3762/bjoc.17.85

• thioglycosides prepared from deoxyfluorinated 1,6-anhydro-2-azido-β-ᴅ-hexopyranose precursors by ring-opening reaction with phenyl trimethylsilyl sulfide. Nucleophilic deoxyfluorination at C4 and C6 by reaction with DAST, thioglycoside hydrolysis and azide/acetamide transformation completed the synthesis

• fulfill this requirement satisfactorily. Accordingly, the synthesis started from known fluorinated 1,6-anhydro-2-azidohexopyranoses 7–13 (Scheme 2) [26][40]. Reaction of compounds 7–10 with phenyl trimethylsilyl sulfide (PhSTMS) and ZnI2 delivered phenyl thioglycosides 14–17 [40]. 1,6-Anhydropyranoses 11

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

• amines with cyanoguanidine in refluxing water in the presence of CuCl2. The pink copper complexes were then treated with hydrogen sulfide to release the desired compounds. As a representative example, N1-butylbiguanide (buformin) was obtained as a hydrochloride salt, with a 47% yield (Scheme 2). Other

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• successfully applied to the gram scale, providing a step towards assorted aryl sulfide structural units with medicinal value. In 2019, Yang and colleagues [52] developed a method for preparing S-aryl dithiocarbamates 135 by a multicomponent reaction of an EDA complex under visible-light irradiation (Scheme 47

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

• Mio Matsumura,
• Takahiro Teramoto,
• Masato Kawakubo,
• Masatoshi Kawahata,
• Yuki Murata,
• Kentaro Yamaguchi,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2021, 17, 671–677, doi:10.3762/bjoc.17.56

• phosphorus atom of 2 was carried out; the results are shown in Scheme 1. The reaction of 2 with hydrogen peroxide or elemental sulfur afforded the corresponding phosphine oxide 3 and sulfide 4 in 92% and 88% yield, respectively. Treatment of 2 with methyl triflate afforded phospholium triflate 5 in 81% yield

• . The reaction of 2 with borane in THF formed a borane complex 6 in 91% yield, and the reaction with chloro(dimethyl sulfide)gold afforded the gold complex 7 in 39% yield. The molecular structures of the synthesized phospholes 2−7 were confirmed by spectral analyses (1H, 13C, and 31P NMR as well as MS

• . For parent compound 2 and derivatives 3, 5, and 6, the HOMO and LUMO correspond to the π and π* orbitals of the benzonaphthophosphoindole skeleton, respectively (Figure S5, Supporting Information File 1). In contrast, the corresponding π orbitals of phosphole sulfide 4 comprise HOMO−2 energy levels

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• -(allylmethylsulfonio)propanoate (AllMSP), were synthesized and fed to marine bacteria from the Roseobacter clade. These bacteria are able to degrade DMSP into dimethyl sulfide and methanethiol. The DMSP analogues were also degraded, resulting in the release of allylated sulfur volatiles known from garlic. For unknown

• giving another example for the complex interactions between marine bacteria and algae. Known DMSP degradation pathways include its hydrolysis to dimethyl sulfide (DMS) and 3-hydroxypropanoic acid (15) by the enzyme DddD [19], or the lysis to DMS and acrylic acid (16) for which various enzymes including

• bacteria from the Roseobacter group that do not naturally occur in these organisms. Results and Discussion 3-(Diallylsulfonio)propanoate (DAllSP) and 3-(allylmethylsulfonio)propanoate (AllMSP) were synthesized by the acid-catalyzed addition of allyl methyl sulfide and diallyl sulfide, respectively, to

The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

• Deniz Tözendemir and
• Cihangir Tanyeli

Beilstein J. Org. Chem. 2021, 17, 494–503, doi:10.3762/bjoc.17.43

• inhibitor activity [33]. Due to the shown biological attractiveness of those 1,3-biarylsulfanyl derivatives, the enantioenriched products can serve as important building blocks for new drugs. The sulfide moiety of β-naphthyl-β-sulfanyl ketones can be oxidized to form sulfones. Despite that sulfones were

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• demethylation pathway by action of the enzymes DmdABCD to methanethiol (MeSH, Scheme 1A) [12] or through lysis by DddD [13] or hydrolytic cleavage by one of the known DMSP lyases (DddW [14], DddP [15], DddQ [16], DddL [17], DddY [18] or DddK [19]) to dimethyl sulfide (DMS, Scheme 1B). It has already been

• . Synthesis of 2-(methyldisulfanyl)benzothiazole (41) 1,2-Bis(benzothiazol-2-yl)disulfane (43, 1.00 g, 3.00 mmol, 1 equiv) and dimethyl sulfide (44, 0.28 g, 3.00 mmol, 1 equiv) were dissolved in dry CH3NO2 (10 mL) and dry CH2Cl2 (10 mL). The solution was cooled to 0 °C and then treated with BF3·Et2O (43 mg

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• bulky sulfur-containing group. The possible pathway for the following cyclization is the Michael addition of the sulfide atom to the central carbon of the acetylacetonate group [38][39][40][41]. The X-ray diffraction study as well as IR and NMR spectroscopy data reveal that in all synthesized compounds

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• sulfide substrates and enhances the approximation of the activated oxygen species to the bonded sulfides. Consequently, the oxidation rate of S-1 is accelerated. In the system COP-1, however, no selective binding exists, so that the activity towards both S-1 and S-2 was similar. Diao and co-workers

Benzothiazolium salts as reagents for the deoxygenative perfluoroalkylthiolation of alcohols

• Armin Ariamajd,
• Nils J. Gerwien,
• Benjamin Schwabe,
• Stefan Dix and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2021, 17, 83–88, doi:10.3762/bjoc.17.8

• the vast majority of cases, the SRF group is not installed as an intact functional group but rather indirectly through perfluoroalkylation of a thiol or sulfide moiety already present on the substrate (Scheme 1a) [15][20][21][22][23][24][25][26]. By contrast, direct perfluoroalkylthiolation, which