- Bifunctionalized Allenes. Part XII. Electrophilic Cyclization and Addition Reactions of 4-Sulfinylated or 4-Sulfonylated Allenecarboxylates
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Reaction of 4-sulfinylated or 4-sulfonylated allenecarboxylates with different electrophilic reagents such as sulfuryl chloride, bromine, benzenesulfenyl, and benzeneselenenyl chlorides takes place with 5-endo-trig cyclization or 3,2-addition reaction depending on the kind of the substituent at the sulfur atom. Treatment of 4-(benzenesulfinyl)-allenoates with electrophiles gives 5-(benzenesulfinyl)-2,5-dihydrofuran-2-ones as a result of the neighboring carboxylate group participation in the cyclization. On the other hand, (3E)-4-(methansulfonyl)alk-3-enoates were prepared by chemo-, regio-, and stereoselective electrophilic addition to the C2-C3-double bond in the allenoate moiety of 4-(methanesulfonyl)allenecarboxylates. When R1 = Me, the treatment with electrophiles gives mixtures of (3E)-4-(methanesulfonyl)alk-3-enoates and (3E)-4-(methanesulfonyl)-2-methylenealk-3-enoates with ratios of about 1.6:1 as a result of addition and elimination reactions. A possible mechanism involving cyclization, addition, and elimination reactions of the 4-sulfinylated or 4-sulfonylated allenecarboxylates is proposed.
- Ivanov, Ivaylo K.,Parushev, Ivaylo D.,Christov, Valerij Ch
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- Synthesis of [2,3]naphthoporphyrins using 4,9-dihydro-4,9-ethano-2H-benz[f]isoindole as a benz[f]isoindole equivalent
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We report a new synthesis of 1,4-dihydro-1,4-ethanonaphthalene using 4,9-dihydro-4,9-ethano-2H-benz[f]isoindole as the equivalent of benz[f]isoindole, from p-benzoquinone as a starting material via the Diels-Alder reaction, Luche reduction, and dehydroxylation. We also report the synthesis of various new [2,3]naphthoporphyrin derivatives and their metal complexes.
- Ishii, Yutaro,Ito, Satoshi,Saito, Yuki,Uno, Daiki,Oba, Toru
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- Group 4 metal complexes bearing thioetherphenolate ligands. Coordination chemistry and ring-opening polymerization catalysis
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A series of group 4 metal complexes 1-4 (1 = (t-BuOS) 2Ti(O-i-Pr)2; 2 = (t-BuOS)2Zr(O-t- Bu)2; 3 = (t-BuOS)2Hf(O-t-Bu)2; 4 = (CumOS)2Zr(O-t-Bu)2) supported by two phenolate bidentate ligands (t-BuOS-H = 4,6-di-tert-butyl-2- phenylsulfanylphenol and CumOS-H = 4,6-dicumyl-2- phenylsulfanylphenol) were synthesized by the reaction of appropriate metal tetra(alkoxide)s with 2 equiv of the ligands. The X-ray structure of 2 revealed that the two ligands were κ2-chelated to the metal center with two phenoxy groups in trans positions and the two thioether moieties in cis positions. VT NMR analysis revealed a fast inversion of configuration at the metal center. Complexes 1-4 promoted the ring-opening polymerization (ROP) of lactide and ε-caprolactone. Complex 4 exhibited the highest activity with a pseudo-first-order rate constant of 0.061 ± 0.003 min-1 at 100 °C, which compares favorably with those reported for the most active group 4 complexes. Polymerizations were well-controlled, giving predictable molecular weights and narrow molecular weight distributions. Essentially atactic PLA were obtained in the ROP of rac-lactide. A DFT study on ROP promoted by these complexes highlighted the importance of the coordinative flexibility of the ancillary ligand to promote monomer coordination at the reactive metal center. In presence of isopropanol, lower PDI indexes and molecular weights of the PLAs proportional to the equivalents of isopropanol suggested that adequate conditions for effective "immortal" polymerizations were achieved. More interestingly, these catalysts promoted the copolymerization of l-lactide and ε-caprolactone. The microstructure disclosed by 13C NMR analysis and the thermal behavior exhibited in DSC studies indicated a random distribution of the two monomer along the polymer chain.
- Della Monica, Francesco,Luciano, Ermanno,Roviello, Giuseppina,Grassi, Alfonso,Milione, Stefano,Capacchione, Carmine
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- NMR chemical shifts and coupling constants of various nuclei of N,N-diethylbenzenesulfenamide, N,N-diethylbenzeneseleneamide and some related sulfur amides
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The 77Se, 15N, 13C, and 1H NMR parameters have been determined for N,N-diethylbenzenesulfen- and N,N-diethylbenzeneseleneamide and 1H-13C coupling constants additionally for N,N-dimethylmethanesulfinamide, N,N-dimethylbenzenesulfinamide, N,N-dimethylmethanesulfonamide, N,N-dimethylbenzenesulfonamide and diphenylsulfone.The nitrogen-15 nucleus is slightly more shielded in the sulfenamide than in the seleneamide.Compared to sulfin- and sulfonamides the nitrogen nuclei of these amides are more shielded.The solvent effects on the chemical shift of both selenium-77 and nitrogen-15 nuclei are observable.The nitrogen-15 chemical shifts of sulfur and seleneamides are less sensitive to the solvents than those of carboxamides.This change in the nitrogen-15 chemical shift in sulfen- and selenamide is the same order of magnitude, but opposite in direction compared with that in sulfon- and sulfinamides.The 1H-13C direct aromatic coupling constants increase along with the increasing oxidation state of sulfur in sulfur amides, being greatest in sulfonamides.
- Ruostesuo, P.,Haekkinen, A.-M,Liias-Lepistoee, R.,Salminen, U.
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- Bifunctionalized allenes. Part XV. Synthesis of 2,5-dihydro-1,2- oxaphospholes by electrophilic cyclization reaction of phosphorylated α-hydroxyallenes
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This paper discusses a reaction of phosphorylated α-hydroxyallenes with protected or unprotected hydroxy groups involving 5-endo-trig cyclizations. Various electrophilic reagents such as sulfuryl chloride, bromine, benzenesulfenyl and benzeneselenenyl chlorides have been applied. The paper describes the reaction of 1-hydroxyalkyl-1,2-dienephosphonates with electrophiles that produces 2-methoxy-2-oxo-2,5-dihydro-1,2-oxaphospholes due to the participation of the phosphonate neighbouring group in the cyclization. On the other hand, (1E)-alk-1-en-1-yl phosphine oxides were prepared as mixtures with 2,5-dihydro-1,2-oxaphosphol-2-ium halides in a ratio of about 1:2 by chemo-, regio, and stereoselective electrophilic addition to the C 2-C3-double bond in the allene moiety and subsequent concurrent attack of the external (halide anion) and internal (phosphine oxide group) nucleophiles. The paper proposes a possible mechanism that involves cyclization and additional reactions of the phosphorylated α- hydroxyallenes.
- Ismailov, Ismail E.,Ivanov, Ivaylo K.,Christov, Valerij Ch.
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- Trifunctionalized allenes. Part III. Electrophilic cyclization and cycloisomerization of 4-phosphorylated 5-hydroxypenta-2,3-dienoates: An expedient synthetic method to construct 2,5-dihydro-1,2-oxaphospholes, furan-2(5H)-ones and 2,5-dihydrofurans
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This chapter discusses the reactions of 4-phosphorylated 5-hydroxypenta-2,3-dienoates with protected or unprotected hydroxy group involving 5-endo-trig cyclizations. Reactions with electrophiles produce mixtures of the 2,5-dihydro-1,2-oxaphosphole-5-carboxylates and the 5-phosphoryl-furan-2(5H)-ones by competitive electrophilic cyclization due to the neighboring phosphonate (phosphine oxide) and the carboxylate groups participation. 4-Phosphorylated 5-hydroxypenta-2,3-dienoates were smoothly converted into the corresponding 4-phosphoryl-2,5-dihydrofuran-2-carboxylates by using 5 mol% of a silver salt as a catalyst in the 5-endo-trig cycloisomerization reaction.
- Ismailov, Ismail E.,Ivanov, Ivaylo K.,Christov, Valerij Ch.
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- Tryptophan trimers and tetramers inhibit dengue and Zika virus replication by interfering with viral attachment processes
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Here, we report a class of tryptophan trimers and tetramers that inhibit (at low micromolar range) dengue and Zika virus infection in vitro. These compounds (AL family) have three or four peripheral tryptophan moieties directly linked to a central scaffold through their amino groups; thus, their carboxylic acid groups are free and exposed to the periphery. Structure-activity relationship (SAR) studies demonstrated that the presence of extra phenyl rings with substituents other than COOH at the N1 or C2 position of the indole side chain is a requisite for the antiviral activity against both viruses. The molecules showed potent antiviral activity, with low cytotoxicity, when evaluated on different cell lines. Moreover, they were active against laboratory and clinical strains of all four serotypes of dengue virus as well as a selected group of Zika virus strains. Additional mechanistic studies performed with the two most potent compounds (AL439 and AL440) demonstrated an interaction with the viral envelope glycoprotein (domain III) of dengue 2 virus, preventing virus attachment to the host cell membrane. Since no antiviral agent is approved at the moment against these two flaviviruses, further pharmacokinetic studies with these molecules are needed for their development as future therapeutic/prophylactic drugs.
- Fikatas, Antonios,Meyen, Eef,Noppen, Sam,Pannecouque, Christophe,Schols, Dominique,Vervaeke, Peter,Camarasa, María-José,Martí-Marí, Olaia,Martínez-Guald, Belén,San-Félix, Ana
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- Total Synthesis of (-)-Cardiopetaline
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The total synthesis of (-)-cardiopetaline, an aconitine-type natural product, has been accomplished. Our synthesis involved a Wagner-Meerwein rearrangement of a sulfonyloxirane that enabled, in a single step, the construction of the bicyclo[3.2.1] system in the aconitine skeleton and effective introduction of oxygen functional groups at the appropriate positions.
- Nishiyama, Yoshitake,Yokoshima, Satoshi,Fukuyama, Tohru
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- Total Synthesis of (?)-Arborisidine
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An asymmetric total synthesis of cage-like indole alkaloid arborisidine is presented. The new synthetic strategy features a catalytic parallel kinetic resolution based on ambident nucleophilicity (C3/N) of indole to set the absolute configurations of the two quaternary chiral centers, and a 5-exo-trig radical cyclization to form the bridged nitrogen-containing five-membered ring.
- Jiao, Lei,Wang, Feng-Yuan
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- A general and concise enantioselective divergent approach to 13-alkyl-substituted ionones
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A novel enantioselective divergent route to 13-alkyl derivatives of a- and g-ionone, important components of perfumes and fragrances, is reported. This relatively short and convenient methodology takes advantage of the use of a common intermediate, easily obtained from highly enantiomerically enriched (S)-a-ionone, which avoids the separate installation of the butenone side chain at C(6) for each analog. Olfactory evaluation of synthesized compounds reconfirmed the influence of the hydrophobic interactions of alkyl substituents at C(5) with olfactory receptors (ORs) in the chemoreception of ionones, and suggested that a synperiplanar orientation of C(13) and the lateral chain is the better geometry fitting OR's cavity.
- Bugoni, Serena,Merlini, Valentina,Porta, Alessio,Zanoni, Giuseppe,Vidari, Giovanni
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- A Divergent Strategy for Site-Selective Radical Disulfuration of Carboxylic Acids with Trisulfide-1,1-Dioxides
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The direct conversion of carboxylic acids into disulfides is described. The approach employs oxidative photocatalysis for base-promoted decarboxylation of the substrate, which yields an alkyl radical that reacts with a trisulfide dioxide through homolytic substitution. The trisulfide dioxides are easily prepared by a newly described approach. 1°, 2°, and 3° carboxylic acids with varied substitution are good substrates, including amino acids and substrates with highly activated C?H bonds. Trisulfide dioxides are also used to achieve the γ-C(sp3)?H disulfuration of amides through a radical relay sequence. In both reactions, the sulfonyl radical that results from substitution propagates the reaction. Factors governing the selectivity of substitution at S2 versus S3 of the trisulfide dioxides have been explored.
- Pratt, Derek A.,Wu, Zijun
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supporting information
p. 15598 - 15605
(2021/06/11)
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- Intramolecular Chalcogenylation of Isooxazolines Mediated by PhICl 2and Diorganyl Disulfides or Diselenides
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Reactive organosulfenyl chlorides (ArSCl) or selenenyl chlorides (ArSeCl), generated in situ from the reaction of PhICl 2with diorganyl disulfides or diselenides, enable the intramolecular oxidative cyclization/chalcogenylation of β,γ-unsaturated oximes, leading to the formation of a series of chalcogenylated isooxazolines in good to excellent yield.
- Du, Yunfei,Li, Xiaoxian,Li, Yadong,Sun, Fengxia,Yu, Zhenyang,Zhang, Dongke,Zhang, Jingran
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- Bifunctional Polyene Cyclizations: Synthetic Studies on Pimarane Natural Products
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Polyene cyclizations generate molecular complexity from a linear polyene in a single step. While methods to initiate these cyclizations have been continuously expanded and improved over the years, the majority of polyene substrates are still limited to simple alkyl-substituted alkenes. In this study, we took advantage of the unique reactivity of higher-functionalized bifunctional alkenes. The realization of a polyene tetracyclization of a dual nucleophilic aryl enol ether involving a transannular endo-termination step enabled the total synthesis of the tricyclic diterpenoid pimara-15-en-3α-8α-diol. The highly flexible and modular route allowed for the preparation of a diverse library of cyclization precursors specifically designed for the total synthesis of the tetracyclic nor-diterpenoid norflickinflimiod C. The tetracyclization of three diversely substituted allenes enabled access to complex pentacyclic products and provided a detailed insight into the underlying reaction pathways.
- Feilner, Julian M.,Magauer, Thomas,Plangger, Immanuel,Wurst, Klaus
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supporting information
p. 12410 - 12421
(2021/07/28)
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- Chromoselective Synthesis of Sulfonyl Chlorides and Sulfonamides with Potassium Poly(heptazine imide) Photocatalyst
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Among external stimuli used to promote a chemical reaction, photocatalysis possesses a unique one—light. Photons are traceless reagents that provide an exclusive opportunity to alter chemoselectivity of the photocatalytic reaction varying the color of incident light. This strategy may be implemented by using a sensitizer capable to activate a specific reaction pathway depending on the excitation light. Herein, we use potassium poly(heptazine imide) (K-PHI), a type of carbon nitride, to generate selectively three different products from S-arylthioacetates simply varying the excitation light and otherwise identical conditions. Namely, arylchlorides are produced under UV/purple, sulfonyl chlorides with blue/white, and diaryldisulfides at green to red light. A combination of the negatively charged polyanion, highly positive potential of the valence band, presence of intraband states, ability to sensitize singlet oxygen, and multi-electron transfer is shown to enable this chromoselective conversion of thioacetates.
- Antonietti, Markus,Guldi, Dirk M.,Markushyna, Yevheniia,Savateev, Aleksandr,Schü?lbauer, Christoph M.,Ullrich, Tobias
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supporting information
p. 20543 - 20550
(2021/08/12)
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- Unified Approach to Benzo[ d]thiazol-2-yl-Sulfonamides
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In this paper, we report a unified approach to N-substituted and N,N-disubstituted benzothiazole (BT) sulfonamides. Our approach to BT-sulfonamides starts from simple commercially available building blocks (benzo[d]thiazole-2-thiol and primary and secondary amines) that are connected via (a) a S oxidation/S-N coupling approach, (b) a S-N coupling/S-oxidation sequence, or via (c) a S-oxidation/S-F bond formation/SuFEx approach. The labile N-H bond in N-monoalkylated BT-sulfonamides (pKa (BTSO2N(H)Bn) = 3.34 ± 0.05) further allowed us to develop a simple weak base-promoted N-alkylation method and a stereoselective microwave-promoted Fukuyama-Mitsunobu reaction. N-Alkyl-N-aryl BT-sulfonamides were accessed with the help of the Chan-Lam coupling reaction. Developed methods were further used in stereo and chemoselective transformations of podophyllotoxin and several amino alcohols.
- Zále?ák, Franti?ek,Ková?, Ond?ej,Lachetová, Eli?ka,?t'astná, Nikola,Pospí?il, Ji?í
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supporting information
p. 11291 - 11309
(2021/09/07)
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- Bifunctionalized allenes. Part XXIV. Competitive electrophilic cyclization of 5-(dimethoxyphosphoryl)-alka-3,4-dienoates leading to 2,5-dihydro-1, 2-oxaphospholes and 5,6-dihydro-2H-pyranes
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We report herein a study on the competitive electrophilic cyclization of 5-(dimethoxyphosphoryl)-alka-3,4-dienoates involving 5-endo-trig and 6-endo-trig mode cyclizations. Reaction with electrophiles produces mixtures of the 2-(2-oxo-2,5-dihydro-1,2-oxaphosphol-5-yl)-alkanoates and (6-oxo-5,6-dihydro-2H-pyran-2-yl)-phosphonates by competitive electrophilic cyclization due to the participation of the neighboring phosphonate and carboxylate groups.
- Christov, Valerij Ch.,Hasanov, Hasan H.,Ivanov, Ivaylo K.
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p. 858 - 870
(2020/11/09)
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- Desulfitative Thioalkylation of Alkenes
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An efficient method for the thioalkylation of alkenes via radical desulfitative sulfur-group transfer is described. The reaction is based on the use of readily available thiosulfonates as starting materials and cheap radical initiators such as dilauroyl peroxide (DLP) and sun lamp irradiation. No transition metal catalyst is required, and the reaction takes place under mild conditions. (Figure presented.).
- Cao, Lidong,Jimeno, Ciril,Renaud, Philippe
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supporting information
p. 3644 - 3648
(2020/08/10)
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- Synthesis of 4-chalcogenyl pyrazoles via electrophilic chalcogenation/cyclization of α,β-alkynic hydrazones
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A facile method for the synthesis of 4-chalcogenylated pyrazoles has been developed via electrophilic chalcogenation/cyclization of α,β-alkynic hydrazones. The cyclization of α,β-alkynic aldehyde hydrazones could be induced by using either sulfenyl chloride or the S-electrophiles generated in situ from the reaction of NCS and arythiol. The developed method was successfully applied to the synthesis of the sulfenyl analogue of celecoxib.
- Cheng, Yu-Fei,Gao, Wen-Chao,Niu, Yulan,Shang, Yu-Zhu,Tian, Jun,Yu, Xinzhang
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p. 1806 - 1811
(2020/03/17)
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- Increasing Scope of Clickable Fluorophores: Electrophilic Substitution of Ylidenemalononitriles
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Recently, we demonstrated that ylidenemalononitriles (YMs) react with amines to form cyclic amidines and that the starting linear YMs are nonemissive in solution and the cyclic amidines are fluorescent. These turn-on systems were of interest to us because of their potential as biosensors and synthons for accessing functionalized pyridines. While our original method was promising, several limitations persisted, including access to more functionalized and polar-solvent-soluble structures as well as increased control over the rate of cyclization. Herein, we report a new approach that allows the electrophilic substitution of YMs. These substituted YMs exhibit faster turn-on rates, color tunability, access to polar-solvent-soluble species, and increased control over cyclization rate. This allowed us to significantly expand the fluorophore's chemical space.
- De Souza, Juliana M.,Abdiaj, Irini,Chen, Jiaqi,Hanson, Kenneth,De Oliveira, Kleber T.,McQuade, D. Tyler
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p. 11822 - 11834
(2020/10/23)
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- Method for preparing 4-benzoyl-4'-methyl-diphenyl sulfide
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The invention relates to a preparation method of a photoinitiator 4-benzoyl-4'-methyl-diphenyl sulfide, in particular to a method for preparing phenyl sulfenyl chloride by taking benzene, sulfur monochloride and chlorine as raw materials, then carrying out thioetherification reaction with toluene, and finally carrying out acylation reaction with benzoyl chloride. According to the preparation method of the 4-benzoyl-4'-methyl-diphenyl sulfide provided by the invention, the shortcomings of an existing method are avoided, the used raw materials are cheap and easy to obtain, the reaction conditions are mild, the method is easy to operate, the yield is high, the cost is low, and the method is suitable for industrial stable production.
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- In Situ Activation of Disulfides for Multicomponent Reactions with Isocyanides and a Broad Range of Nucleophiles
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Activation of disulfides with N-halogen succinimide in the presence of TEMPO allows insertion reaction by an isocyanide, the product of which can further accept a wide range of nucleophiles for the generation of isothioureas and related molecular moieties. This new procedure overcomes previous methods that accept essentially only aryl amines as the third nucleophilic component. The diverse nucleophiles usable in our new protocol make this approach a general method for de novo synthesis of many S-containing heterocycles.
- Lei, Xiaofang,Wang, Yuanyuan,Fan, Erkang,Sun, Zhihua
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supporting information
p. 1484 - 1487
(2019/02/26)
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- Synthetic method of aryl sulfur chlorine or aryl selenium chlorine
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The invention discloses a synthetic method of aryl sulfur chlorine or aryl selenium chlorine. The synthetic method comprises the following steps that diaryl disulfide or diaryl diselenide II is dissolved in a solvent and reacts under the action of dichloro-iodobenzene III to obtain aryl sulfur chlorine or aryl selenium chlorine I. In the formula shown in the description, R refers to hydrogen, methyl or halogen, and Y refers to sulfur or selenium. The method has the advantages that the operation is simple, the raw materials are cheap and easy to obtain, the yield is relatively ideal and the cost is low.
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Paragraph 0021-0024
(2019/06/27)
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- In Situ Formation of RSCl/ArSeCl and Their Application to the Synthesis of 4-Chalcogenylisocumarins/Pyrones from o-(1-Alkynyl)benzoates and (Z)-2-Alken-4-ynoates
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The reaction of diorganyl disulfides or diselenides with PhICl2 in acetonitrile was found for the first time to lead to the in situ formation of organosulfenyl chloride or selenenyl chloride, which enables the regioselective intramolecular chalcogenylacyloxylation of alkynes resulting in the formation of 4-chalcogenylisocumarins/pyrones in good to excellent yields under metal-free conditions.
- Xing, Linlin,Zhang, Yong,Li, Bing,Du, Yunfei
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supporting information
p. 3620 - 3624
(2019/05/24)
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- Organophosphorus-Catalyzed Deoxygenation of Sulfonyl Chlorides: Electrophilic (Fluoroalkyl)sulfenylation by PIII/PV=O Redox Cycling
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A method for electrophilic sulfenylation by organophosphorus-catalyzed deoxygenative O-atom transfer from sulfonyl chlorides is reported. This C?S bond-forming reaction is catalyzed by a readily available small-ring phosphine (phosphetane) in conjunction with a hydrosilane terminal reductant to afford a general entry to sulfenyl electrophiles, including valuable trifluoromethyl, perfluoroalkyl, and heteroaryl derivatives that are otherwise difficult to access. Mechanistic investigations indicate that the twofold deoxygenation of the sulfonyl substrate proceeds by the intervention of an off-cycle resting state thiophosphonium ion. The catalytic method represents an operationally simple protocol using a stable phosphine oxide as a precatalyst and exhibits broad functional-group tolerance.
- Ghosh, Avipsa,Lecomte, Morgan,Kim-Lee, Shin-Ho,Radosevich, Alexander T.
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supporting information
p. 2864 - 2869
(2019/02/01)
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- Merging Photoredox PCET with Ni-Catalyzed Cross-Coupling: Cascade Amidoarylation of Unactivated Olefins
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The integration of amidyl radicals with cross-coupling chemistry opens new avenues for reaction design. However, the lack of efficient methods for the generation of such radical species has prevented many such transformations from being brought to fruition. Herein, the amidoarylation of unactivated olefins by a cascade process from non-functionalized amides is reported by merging, for the first time, photoredox proton-coupled electron transfer (PCET) with nickel catalysis. This new technology grants access to an array of complex molecules containing a privileged pyrrolidinone core from alkenyl amides and aryl- and heteroaryl halides in the presence of a visible light photocatalyst and a nickel catalyst. Notably, the reaction is not restricted to amides—carbamates and ureas can also be used. Mechanistic studies, including hydrogen-bond affinity constants, cyclization rate measurements, quenching studies, and cyclic voltammetry, were central to comprehend the subtleties contributing to the integration of the two catalytic cycles. A rapid, highly diastereoselective amidoarylation of unactivated olefins was achieved to render medicinally privileged pyrrolidinone structures. Taking advantage of a photoredox proton-coupled electron transfer process, amidyl radicals were obtained from non-prefunctionalized N–H bonds under mild conditions, which were subsequently trapped by pendant olefins, delivering alkyl radicals for nickel-catalyzed cross-coupling. Mechanistic studies revealed the key balance between thermodynamically-driven radical generation and kinetically-driven cyclization, which led to expanding the scope toward urea and carbamate substrates. Rapid generation of molecular complexity and access to novel 3D chemical space is pivotal for successful and efficient drug discovery. Nickel/photoredox dual catalysis has arisen as an appealing strategy toward such a goal by rapidly introducing Csp3 centers under mild reaction conditions. By taking advantage of a native amide group, we achieved an amidoarylation reaction of unactivated olefins, rendering a series of medicinally privileged structures in a highly atom-economical way. The reaction takes advantage of a photoredox proton-coupled electron transfer event to cleave the strong amidyl N–H bond homolytically. Subsequent regiospecific 5-exo-trig cyclization generates an alkyl radical. High functional group tolerance was achieved with excellent diastereoselectivities owing to the reaction's mild nature. Mechanistic studies showed the intricate relationship between the base stoichiometry and the N–H donor, as well as the key balance between kinetic and thermodynamic factors.
- Zheng, Shuai,Gutiérrez-Bonet, álvaro,Molander, Gary A.
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supporting information
p. 339 - 352
(2019/02/14)
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- Synthesis of Enhanced, Isolable Disulfanium Salts and their Application to Thiiranium-Promoted Polyene Cyclizations
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Although electrophile-promoted polyene cyclizations have long been a mainstay transformation for the rapid and stereocontrolled preparation of varied natural products and designed molecules, efforts to effect sulfur-promoted variants have arguably lagged behind other counterparts. This state of affairs is particularly true with alkyl sulfide-based electrophiles, even in racemic variants. Herein, building on previously reported discoveries, is described a distinct and modular method to prepare a range of isolable alkyl and aryl disulfanium salts that can affect thiiranium-based polyene cyclizations in moderate to good yields. In most of the substrates probed, these reagents provide superior yields to previously reported alternatives. In addition, initial efforts to develop an asymmetric variant of the process through the use of chiral versions of these reagents are discussed.
- Cole, Charles J. F.,Chi, Hyung Min,Debacker, Kenneth C.,Snyder, Scott A.
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p. 4351 - 4358
(2018/06/26)
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- Sulfides and Disulfides of s-Triazine: Potential Thermal Thiyl Radical Generators
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A series of aliphatic and aromatic thioethers and dithioethers of s-triazine were synthesised to study their thermal properties, in particular the thermally induced thiyl radical generation ability. Four symmetric s-triazine sulfides of the type (RS)3C3N3, namely 2,4,6-tris(phenylthio)- (1), 2,4,6-tris(para-tolylthio)- (3), 2,4,6-tris(ethylthio)- (5) and 2,4,6-tris(tert-butylthio)-1,3,5-triazine (7), as well as four symmetric s-triazine disulfides of the type (RSS)3C3N3, namely 2,4,6-tris(phenyldithio)- (2), 2,4,6-tris(para-tolyldithio)- (4), 2,4,6-tris(ethyldithio)- (6) and 2,4,6-tris(tert-butyldithio)-1,3,5-triazine (8) were synthesised. All compounds were comprehensively characterised by 1H and 13C NMR, infrared and Raman spectroscopy as well as elemental analyses. Single-crystal X-ray diffraction analyses of 1, 2 and 5 are discussed. The thermal behaviour was studied by thermogravimetric analyses coupled with mass spectrometry (TGA-MS) and quantum chemical calculations. Limiting oxygen index (LOI) flammability tests showed that the disulfides are the most promising radical generators, and are most likely suitable flame retardants for selected polymers.
- H?hne, Carl-Christoph,Posern, Christian,B?hme, Uwe,Kroke, Edwin
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p. 13596 - 13606
(2018/09/19)
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- Generation of 1,2-oxathiolium ions from (arysulfonyl)- and (arylsulfinyl)allenes in Br?nsted acids. NMR and DFT study of these cations and their reactions
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In strong Br?nsted acids (CF3SO3H, FSO3H, D2SO4), (arysulfonyl)allenes (ArSO2-CR1=C=CR2R3) and (arylsulfinyl)allenes (ArSO-CR1=C=CR2R3) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl, leads to their deprotonation with a stereoselective formation of (arysulfonyl)butadienes (for instance, ArSO2-CR1=C-C(Me)=CH2, for R2 = R3 = Me, yields of 87-98%). Reactions of (arysulfonyl)allenes in the system TfOH (0.1 equiv)-HFIP (hexafluoropropan-2-ol) followed by hydrolysis give rise to allyl alcohols (ArSO2-CR1=CH-C(OH)R2R3, yields of 78-99%). Reflux of solutions of (arysulfonyl)allenes in the presence of TfOH (1 equiv) in 1,2-dichlorobenzene leads to the cyclization into thiochromene 1,1-diox-ides in high yields. Under the action of TfOH or AlX3 (X = Cl, Br) followed by hydrolysis of reaction mixtures, (arylsulfinyl)allenes give allyl alcohols (ArSO2-CR1=CH-C(OH)R2R3). Plausible reaction mechanisms have been proposed for all studied reactions.
- Lozovskiy, Stanislav V.,Ivanov, Alexander Yu.,Khoroshilova, Olesya V.,Vasilyev, Aleksander V.
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p. 2897 - 2906
(2018/12/13)
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- Synthesis and Deployment of an Elusive Fluorovinyl Cation Equivalent: Access to Quaternary α-(1′-Fluoro)vinyl Amino Acids as Potential PLP Enzyme Inactivators
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Developing specific chemical functionalities to deploy in biological environments for targeted enzyme inactivation lies at the heart of mechanism-based inhibitor development but also is central to other protein-tagging methods in modern chemical biology including activity-based protein profiling and proteolysis-targeting chimeras. We describe here a previously unknown class of potential PLP enzyme inactivators; namely, a family of quaternary, α-(1′-fluoro)vinyl amino acids, bearing the side chains of the cognate amino acids. These are obtained by the capture of suitably protected amino acid enolates with β,β-difluorovinyl phenyl sulfone, a new (1′-fluoro)vinyl cation equivalent, and an electrophile that previously eluded synthesis, capture and characterization. A significant variety of biologically relevant AA side chains are tolerated including those for alanine, valine, leucine, methionine, lysine, phenylalanine, tyrosine, and tryptophan. Following addition/elimination, the resulting transoid α-(1′-fluoro)-β-(phenylsulfonyl)vinyl AA-esters undergo smooth sulfone-stannane interchange to stereoselectively give the corresponding transoid α-(1′-fluoro)-β-(tributylstannyl)vinyl AA-esters. Protodestannylation and global deprotection then yield these sterically encumbered and densely functionalized quaternary amino acids. The α-(1′-fluoro)vinyl trigger, a potential allene-generating functionality originally proposed by Abeles, is now available in a quaternary AA context for the first time. In an initial test of this new inhibitor class, α-(1′-fluoro)vinyllysine is seen to act as a time-dependent, irreversible inactivator of lysine decarboxylase from Hafnia alvei. The enantiomers of the inhibitor could be resolved, and each is seen to give time-dependent inactivation with this enzyme. Kitz-Wilson analysis reveals similar inactivation parameters for the two antipodes, L-α-(1′-fluoro)vinyllysine (Ki = 630 ± 20 μM; t1/2 = 2.8 min) and D-α-(1′-fluoro)vinyllysine (Ki = 470 ± 30 μM; t1/2 = 3.6 min). The stage is now set for exploration of the efficacy of this trigger in other PLP-enzyme active sites.
- McCune, Christopher D.,Beio, Matthew L.,Sturdivant, Jill M.,De La Salud-Bea, Roberto,Darnell, Brendan M.,Berkowitz, David B.
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supporting information
p. 14077 - 14089
(2017/10/17)
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- Evolution of a Polyene Cyclization Cascade for the Total Synthesis of (?)-Cyclosmenospongine
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We report a full account on the development of a unique cationic polyene cyclization for the total synthesis of the tetracyclic meroterpenoid (?)-cyclosmenospongine. A highly convergent three-component coupling strategy enabled rapid access to individual cyclization precursors that were tested for their reactivity. The successful transformation generates three rings and sets four consecutive stereocenters in a single operation proceeding in a highly efficient manner to give exclusively the trans-decalin framework. In addition, we found that the enol ether geometry and the relative configuration of C3 and C8 are crucial for the success of the polyene cyclization.
- Speck, Klaus,Magauer, Thomas
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supporting information
p. 1157 - 1165
(2017/02/05)
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- Desulfurative Chlorination of Alkyl Phenyl Sulfides
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The chlorination of readily available secondary and tertiary alkyl phenyl sulfides using (dichloroiodo)benzene (PhICl2) is reported. This mild and rapid nucleophilic chlorination is extended to sulfa-Michael derived sulfides, affording elimination-sensitive β-chloro carbonyl and nitro compounds in good yields. The chlorination of enantioenriched benzylic sulfides to the corresponding inverted chlorides proceeds with high stereospecificity, thus providing a formal entry into enantioenriched chloro-Michael adducts. A mechanism implying the formation of a dichloro-λ4-sulfurane intermediate is proposed.
- Canestrari, Daniele,Lancianesi, Stefano,Badiola, Eider,Strinna, Chiara,Ibrahim, Hasim,Adamo, Mauro F. A.
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supporting information
p. 918 - 921
(2017/02/26)
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- Controlled Intercalation and Chemical Exfoliation of Layered Metal-Organic Frameworks Using a Chemically Labile Intercalating Agent
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Creating ordered two-dimensional (2D) metal-organic framework (MOF) nanosheets has attracted extensive interest. However, it still remains a great challenge to synthesize ultrathin 2D MOF nanosheets with controlled thickness in high yields. In this work, we demonstrate a novel intercalation and chemical exfoliation approach to obtain MOF nanosheets from intrinsically layered MOF crystals. This approach involves two steps: first, layered porphyrinic MOF crystals are intercalated with 4,4′-dipyridyl disulfide through coordination bonding with the metal nodes; subsequently, selective cleavage of the disulfide bond induces exfoliation of the intercalated MOF crystals, leading to individual freestanding MOF nanosheets. This chemical exfoliation process can proceed efficiently at room temperature to produce ultrathin (~1 nm) 2D MOF nanosheets in ~57% overall yield. The obtained ultrathin nanosheets exhibit efficient and far superior heterogeneous photocatalysis performance compared with the corresponding bulk MOF.
- Ding, Yanjun,Chen, Ying-Pin,Zhang, Xinlei,Chen, Liang,Dong, Zhaohui,Jiang, Hai-Long,Xu, Hangxun,Zhou, Hong-Cai
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supporting information
p. 9136 - 9139
(2017/07/22)
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- Betamethasone preparation method
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The invention discloses a betamethasone preparation method. The method includes steps: (1) in existence of weak-acid weak-base salts, taking a compound in a formula A as a starting raw material, and subjecting to reaction with benzenesulfenyl chloride to obtain a compound B; (2) taking the compound B as a raw material to obtain betamethasone by synthesis, wherein a reaction formula is as shown in the specification. The betamethasone preparation method has advantages that industrial mass production is benefited due to avoiding of cyanides and heavy metals, the yield which is 126% is much higher than that in the prior art, production cost is reduced, technical improvement on a preparation process of steroids such as betamethasone with C17 side chains is promoted, and ideas are provided for preparation of the steroids with side chains.
- -
-
Paragraph 0064; 0065
(2017/08/31)
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- Preparation method of key midbody allene sulfoxide matter of dexamethasone
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The invention discloses a preparation method of key midbody allene sulfoxide matter of dexamethasone. The preparation method includes steps of adding an organic solvent (I) containing weak acid and weak base salt to a compound shown in Formula A; then adding to an organic solvent (II) containing chorine fenbendazole and reacting; after reaction, collecting a compound shown in Formula B from a reaction product. The method has the beneficial effects that the product does not use cyanide and heavy metals, and is good for large-scale industrial production; the yield is over 124%, which is greatly higher than that of the prior art; the production cost is reduced, and the technical innovation of the preparation technique of dexamethasone and other steroids containing C17 side chain is promoted; meanwhile, the method also provides a thinking for the preparation of the steroids with the side chain. The reaction general formula is shown as below: FORMULA.
- -
-
Paragraph 0060; 0061
(2017/08/31)
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- Benzoporphyrins: Selective Co-sensitization in Dye-Sensitized Solar Cells
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A novel class of dyes, namely benzoporphyrins, was synthesized and implemented into dye-sensitized solar cells. They feature complementary absorptions compared to N719, which renders them promising candidates for co-sensitization in DSSCs. Notably, metallated benzoporphyrins reveal a TiO2-nanoparticle attachment that is size and aggregation dependent. Therefore, unproductive energy-transfer events between the selectively attached dyes can be prevented. In light of the latter, an efficiency improvement of 39 % has been achieved upon selective adsorption of benzoporphyrins and N719 onto different layers of TiO2 photoelectrode.
- Lodermeyer, Fabian,Costa, Rubén D.,Malig, Jenny,Jux, Norbert,Guldi, Dirk M.
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supporting information
p. 7851 - 7855
(2016/06/09)
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- A Failed Late-Stage Epimerization Thwarts an Approach to Ineleganolide
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Significant efforts were made to complete a synthesis of the complex norcembranoid ineleganolide via a seemingly attractive strategy involving late-stage creation of the central seven-membered ring. While the two key enantioenriched building blocks were made via high-yielding sequences and their convergent union was efficient, the critical C4-C5 bond of this sterically congested natural product could never be forged. Several interesting examples of unexpected acid-base behavior and unanticipated proximity-induced reactivity accounted for most of the problems in the execution of the synthesis plan.
- Horn, Evan J.,Silverston, Joel S.,Vanderwal, Christopher D.
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p. 1819 - 1838
(2016/03/15)
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- Efficient synthesis of 5-chalcogenyl-1,3-oxazin-2-ones by chalcogen-mediated yne-carbamate cyclisation: An experimental and theoretical study
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A very efficient synthesis of 5-chalcogenyl-1,3-oxazin-2-ones has been accomplished by the chalcogen-mediated yne-carbamate cyclisation of chiral, non-racemic N-Cbz-protected propargylic amines using PhXY (X = Se, S, Te; Y = Br or Cl) as electrophile sources. The reactions gave good-toexcellent yields for a wide range of substrates. In all cases the reaction was totally regioselective, occurring by a 6-endo-dig process regardless of the nature of the reagent and of the substituents in the starting material. This methodology permits the formation of the 1,3-oxazin-2-one moiety as well as the simultaneous installation of a chalcogen functionality onto the heterocyclic ring. The experimental results have been rationalised by theoretical studies at the B3LYP/6-311G level of theory.
- Monlen, Alicia,Blay, Gonzalo,Domingo, Luis R.,Muoz, M. Carmen,Pedro, Jos R.
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supporting information
p. 1020 - 1027
(2015/02/19)
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- Novel triazole-based compounds and herbicides containing the same
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The present invention refers to plant biotin biosynthetic enzyme a kappa synthases method for inhibiting the growth of plant and consequently inhibits the triazole compounds novel causes the virus to be an environmentally benign process and relates to herbicides.
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-
Paragraph 0101; 0110; 0111
(2016/10/20)
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- meso-Tetraphenylporphyrin with a pi-system extended by fusion with anthraquinone
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Fusion with a 9,10-anthraquinone moiety was achieved to extend porphyrin's π-system. A bridged dihydroisoindole derivative was used to prepare the corresponding meso-tetraphenyltetraanthraquinonoporphyrin (Ph4TAQP) via a thermal retro-Diels-Alder reaction. The basic optical properties of the prepared new anthraquinonoporphyrin and its complexes with Zn and Pd were studied.
- Filatov, Mikhail A.,Heinrich, Ernesta,Landfester, Katharina,Baluschev, Stanislav
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p. 6977 - 6983
(2015/06/25)
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- TFA-promoted direct C-H sulfenylation at the C2 position of non-protected indoles
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A simple, efficient and practical metal-free C-H sulfenylation process at the C2 position of non-protected indoles has been developed. 2-Thioindoles were obtained in moderate to high yields using stable and readily available N-(thio)succinimides at room temperature in the presence of TFA.
- Hostier, Thomas,Ferey, Vincent,Ricci, Gino,Pardo, Domingo Gomez,Cossy, Janine
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supporting information
p. 13898 - 13901
(2015/09/07)
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- Bifunctionalized allenes, part XI: Competitive electrophilic cyclization and addition reactions of 4-phosphorylated allenecarboxylates
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The reaction of the 4-phosphorylated allenecarboxylates with different electrophilic reagents such as sulfuryl chloride, bromine, benzenesulfanyl, and benzeneselanyl chlorides takes place with a 5-endo-trig cyclization or 2,3-addition reaction depending on the kind of the substituents in the phosphoryl group. Treatment of the 4-(dimethoxyphosphopyl)-allenoates with electrophiles gives a mixture of 2,5-dihydro-1,2-oxaphospholes and furan-2(5H)-ones in the ratio of about 1.7:1 as a result of the neighboring group participation of phosphonate and carboxylate groups in the cyclization. On the other hand, (3E)-4-(diphenylphosphoryl)-alk-3-enoates were prepared, in moderate yields, by chemo-, regio, and stereoselective electrophilic addition to the C2i£C3-double bond in the allenoate moiety. A possible mechanism involving cyclization and addition reactions of the 4-phosphorylated allenecarboxylates was proposed.
- Ivanov, Ivaylo K.,Parushev, Ivaylo D.,Christov, Valerij Ch.
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- Palladium-catalyzed regio- and stereoselective chlorothiolation of terminal alkynes with sulfenyl chlorides
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Chlorothiolation of terminal alkynes with sulfenyl chlorides yields anti-adducts without transition-metal catalysts. In sharp contrast, transition-metal-catalyzed chlorothiolation has not been developed to date, possibly because organosulfur compounds can poison catalyst. Herein, the regio- and stereoselective palladium-catalyzed chlorothiolation of terminal alkynes with sulfenyl chlorides is described. syn-Chlorothiolation offers a complementary synthetic route to chloroalkenyl sulfides. 2-Chloroalkenyl sulfides can easily be transformed into various sulfur-containing products, most of which are often found in natural products and pharmaceuticals. Copyright
- Iwasaki, Masayuki,Fujii, Tomoya,Yamamoto, Arisa,Nakajima, Kiyohiko,Nishihara, Yasushi
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supporting information
p. 58 - 62
(2014/01/06)
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- Iron-Induced regio- and stereoselective addition of sulfenyl chlorides to alkynes by a radical pathway
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The radical addition of the ClS s-bond in sulfenyl chlorides to various C~C triple bonds has been achieved with excellent regio- and stereoselectivity in the presence of a catalytic amount of a common iron salt. The reaction is compatible with a variety of functional groups and can be scaled up to the gram-scale with no loss in yield. As well as terminal alkynes, internal alkynes underwent stereodefined chlorothiolation to provide tetrasubstituted alkynes. Preliminary mechanistic investigations revealed a plausible radical process involving a sulfur-centered radical intermediate via iron-mediated homolysis of the ClS bond. The resulting chlorothiolation adducts can be readily transformed to the structurally complex alkenyl sulfides by cross-coupling reactions. The present reaction can also be applied to the complementary synthesis of the potentially useful bis-sulfoxide ligands for transition-metal-catalyzed reactions.
- Iwasaki, Masayuki,Fujii, Tomoya,Nakajima, Kiyohiko,Nishihara, Yasushi
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supporting information
p. 13880 - 13884
(2015/01/16)
-
- Synthesis and biological evaluation of nonsymmetrical aromatic disulfides as novel inhibitors of acetohydroxyacid synthase
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46 Novel nonsymmetrical aromatic disulfides containing [1,3,4]thiadiazole or [1,3,4]oxadiazole groups were synthesized and their biological activities were evaluated as inhibitors of acetohydroxyacid synthase (AHAS, EC 2.2.1.6). Besides their strong in vitro inhibition against plant AHAS, compounds 3e and 3f also display 80-100% post-emergence herbicidal activities in greenhouse bioassay at 1500 g/ha dosage. The assay of exogenous branched-chain amino acids supplementation on rape root growth of 3e suggests that the herbicidal activity has relationship with AHAS inhibition.
- Li, Zai-Shun,Wang, Wei-Min,Lu, Wei,Niu, Cong-Wei,Li, Yong-Hong,Li, Zheng-Ming,Wang, Jian-Guo
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supporting information
p. 3723 - 3727
(2013/07/25)
-
- Synthesis and evaluation of novel sulfenamides as novel anti Methicillin-resistant Staphylococcus aureus agents
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A total of 29 novel sulfenamide compounds were synthesized, spectroscopically characterized and evaluated in vitro for antimicrobial activity against various infectious pathogens. Compounds 1b and 2c exhibited potent inhibition against clinical Methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentration (MIC) values of 1.56 μg/mL.
- Shang, Jian-Li,Guo, Hui,Li, Zai-Shun,Ren, Biao,Li, Zheng-Ming,Dai, Huan-Qin,Zhang, Li-Xin,Wang, Jian-Guo
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supporting information
p. 724 - 727
(2013/02/25)
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- Total synthesis of the postulated structure of fulicineroside
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A total synthesis of the proposed structures of fulicineroside and its aglycone fulicinerine is reported. The tetrasubstituted dibenzofuran substructure was accessible either through a Pd-mediated ortho-metalation or by an Ir-catalyzed meta-borylation. The synthesis of the β,β,α- linked trisaccharide consisting of D-olivose, L-rhodinose, and L-rhamnose was challenged by the unprecedented β-linked rhodinose. A Pd-catalyzed β-selective glycosylation of a 4-epi-rhodinose and a subsequent Mitsunobu inversion provided selectively the β-linked L-rhodinose-L-rhamnose disaccharide. Comparison with the reported data for the natural product and the aglycone suggests a misassignment of the structure of the natural product. Natural product reassignment: Total synthesis of the proposed structures for fulicineroside and its aglycone fulicinerine has been achieved (see figure). Key issues were the tetrasubstituted dibenzofuran and the trisaccharide with its β-linkage between L-rhodinose and L-rhamnose. A comparison with the reported data for the natural product and the aglycone suggests a misassignment of the structure of the natural product. Copyright
- Bartholom?us, Ruben,Dommershausen, Fabian,Thiele, Markus,Karanjule, Narayan S.,Harms, Klaus,Koert, Ulrich
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supporting information
p. 7423 - 7436
(2013/06/27)
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- Synthesis of aryl thioethers through the N -chlorosuccinimide-promoted cross-coupling reaction of thiols with Grignard reagents
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A convenient one-pot approach for the synthesis of aryl sulfides through the coupling of thiols with Grignard reagents in the presence of N-chlorosuccinimide is described. The sulfenylchlorides were formed when thiols were treated with N-chlorosuccinimide, and the resulting sulfenylchlorides were then directly reacted with Grignard reagents to provide aryl sulfides in good to excellent yields under mild reaction conditions. Functional groups including ester, fluoro, and chloro are tolerated by the reaction conditions employed. It is important to note that this method has a short reaction time (30 min in total) and represents an alternative approach for the synthesis of aryl sulfides over the existing protocols.
- Cheng, Jun-Hao,Ramesh, Chintakunta,Kao, Hsin-Lun,Wang, Yu-Jen,Chan, Chien-Ching,Lee, Chin-Fa
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p. 10369 - 10374
(2013/01/15)
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- Tetraaryltetraanthra[2,3]porphyrins: Synthesis, structure, and optical properties
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A synthetic route to symmetrical tetraaryltetraanthra[2,3]porphyrins (Ar4TAPs) was developed. Ar4TAPs bearing various substituents in meso-phenyls and anthracene residues were prepared from the corresponding pyrrolic precursors. The synthesized porphyrins possess high solubility and exhibit remarkably strong absorption bands in the near-infrared region (790-950 nm). The scope of the method, selection of the peripheral substituents, choice of the metal, and their influence on the optical properties are discussed together with the first X-ray crystallographic data for anthraporphyrin.
- Filatov, Mikhail A.,Baluschev, Stanislav,Ilieva, Iliyana Z.,Enkelmann, Volker,Miteva, Tzenka,Landfester, Katharina,Aleshchenkov, Sergey E.,Cheprakov, Andrei V.
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p. 11119 - 11131
(2013/02/26)
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- Synthesis of sulfenamides from aminoesters and their stability
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A series of sulfenamides is derived from α-amino esters for the first time. Stabilities of synthesized compounds are studied and attempts have been made to increase their half-lives.
- Ashiq, Muhammad Irfan,Hussain, Ishtiaq,Tariq, Muhammad Ilyas,Kilburn, Jeremy,Siddiqui, Hamid Latif
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p. 1460 - 1463
(2013/05/08)
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- A traceless, one-pot preparation of unsymmetric disulfides from symmetric disulfides through a repeated process involving sulfenic acid and thiosulfinate intermediates
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A variable group of unsymmetric disulfides was prepared under mild reaction conditions and in high yields through the reaction of symmetric disulfides with sulfuryl chloride followed by treatment with thiols in the presence of water.
- Han, Minsoo,Lee, Jong Tak,Hahn, Hoh-Gyu
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experimental part
p. 236 - 239
(2011/02/28)
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- Catalytic thia-Sommelet-Hauser rearrangement: Application to the synthesis of oxindoles
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A series of 3-arylthio-1,3-disubstituted-oxindoles were prepared in good yields by the reaction of α-diazocarbonyl compounds and sulfenamides. The reaction involves a Rh-catalyzed thia-Sommelet-Hauser-type rearrangement.(Figure Presented)
- Li, Yuye,Shi, Yi,Huang, Zhongxing,Wu, Xinhu,Xu, Pengfei,Wang, Jianbo,Zhang, Yan
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supporting information; experimental part
p. 1210 - 1213
(2011/04/27)
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