- Bimetallic Cooperative Catalysis for Decarbonylative Heteroarylation of Carboxylic Acids via C-O/C-H Coupling
-
Cooperative bimetallic catalysis is a fundamental approach in modern synthetic chemistry. We report bimetallic cooperative catalysis for the direct decarbonylative heteroarylation of ubiquitous carboxylic acids via acyl C-O/C-H coupling. This novel catalytic system exploits the cooperative action of a copper catalyst and a palladium catalyst in decarbonylation, which enables highly chemoselective synthesis of important heterobiaryl motifs through the coupling of carboxylic acids with heteroarenes in the absence of prefunctionalization or directing groups. This cooperative decarbonylative method uses common carboxylic acids and shows a remarkably broad substrate scope (>70 examples), including late-stage modification of pharmaceuticals and streamlined synthesis of bioactive agents. Extensive mechanistic and computational studies were conducted to gain insight into the mechanism of the reaction. The key step involves intersection of the two catalytic cycles via transmetallation of the copper–aryl species with the palladium(II) intermediate generated by oxidative addition/decarbonylation.
- Liu, Chengwei,Ji, Chong-Lei,Zhou, Tongliang,Hong, Xin,Szostak, Michal
-
supporting information
p. 10690 - 10699
(2021/04/09)
-
- A 2, 5 - diaryl five-membered heterocyclic aromatic preparation method
-
The invention relates to a 2, 5 - diaryl five-membered heterocyclic aromatic preparation method, the method is to turn the diaryl Iodized salt compounds, five-membered heterocyclic aromatic compound, catalyst, ligand, alkali and solvent are mixed uniformly, in 100 °C -140 °C lower sealing reaction for 24 hours, the reaction solution obtained after the reaction is complete; the reaction solution are often gauge extraction, drying, concentration, column chromatography separation to obtain the 2, 5 - diaryl five-membered heterocyclic aromatic compounds. The invention belongs to a pot of reaction of the atom economy, simple operation, high yield, can realize the large-scale production, in functional organic material, biological active compounds and pharmaceutical synthesis of better industrial application prospect.
- -
-
Paragraph 0021; 0022; 0023-0026; 0039-0041
(2019/05/15)
-
- Cu-Catalyzed Aerobic Oxidative Sulfuration/Annulation Approach to Thiazoles via Multiple Csp3-H Bond Cleavage
-
A novel and practical Cu-catalyzed aerobic oxidative synthesis of thiazoles was developed. This chemistry for the first time achieved thiazole construction from simple aldehydes, amines, and element sulfur through multiple Csp3-H bond cleavage processes. Molecular oxygen was used as a green oxidant in this oxidative protocol. The substrate scope is broad with the tolerance of aliphatic amines. The mechanistic study might promote the reaction design for a new sulfuration/annulation reaction with readily available element sulfur.
- Wang, Xiaoyang,Qiu, Xu,Wei, Jialiang,Liu, Jianzhong,Song, Song,Wang, Wen,Jiao, Ning
-
supporting information
p. 2632 - 2636
(2018/05/22)
-
- One-Pot Strategy for Thiazoline Synthesis from Alkenes and Thioamides
-
A convenient synthesis of a privileged pharmaceutical motif, thiazoline is accomplished. This reaction utilizes simple and readily available alkene and thioamide substrates in an intermolecular fashion via a simple one-pot procedure. A wide range of functional groups is tolerated, and the thiazoline product has been further utilized for the synthesis of the corresponding β-aminothiol and thiazole from routine hydrolysis and oxidation protocols.
- Alom, Nur-E,Wu, Fan,Li, Wei
-
supporting information
p. 930 - 933
(2017/02/26)
-
- Substituted azole penta-heterocyclic derivatives and solvothermal one-pot synthesis method and application thereof
-
The invention belongs to the technical field of organic synthesis and particularly discloses a series of substituted azole penta-heterocyclic derivatives and a solvothermal one-pot synthesis method thereof. By the adoption of the solvothermal one-pot synthesis method for preparing the target product, reaction time is short, a solvent is not prone to volatilization in an airtight system, recycling can be realized, production cost is effectively reduced, the advantages of energy conservation and environment friendliness are achieved, operation is easy, yield is high, and the prepared substituted azole penta-heterocyclic derivatives have good anti-microbial biological activity and excellent photophysical properties such as electron conductivity, the fluorescence property and the ultraviolet property, thereby having very high development and application value.
- -
-
Paragraph 0083; 0084; 0085
(2016/11/02)
-
- A trifluorinated thiazoline scaffold leading to pro-apoptotic agents targeting prohibitins
-
A new class of small molecules, with an unprecedented trifluorothiazoline scaffold, were synthesized and their pro-apoptotic activity was evaluated. With an EC50 in the low micromolar range, these compounds proved to be potent inducers of apopt
- Pérez-Perarnau, Alba,Preciado, Sara,Palmeri, Claudia Mariela,Moncunill-Massaguer, Cristina,Iglesias-Serret, Daniel,González-Gironès, Diana M.,Miguel, Miriam,Karasawa, Satoki,Sakamoto, Satoshi,Cosialls, Ana M.,Rubio-Pati?o, Camila,Saura-Esteller, José,Ram?n, Rosario,Caja, Laia,Fabregat, Isabel,Pons, Gabriel,Handa, Hiroshi,Albericio, Fernando,Gil, Joan,Lavilla, Rodolfo
-
supporting information
p. 10150 - 10154
(2015/03/31)
-
- Facile Synthesis of 2,5-Disubstituted Thiazoles from Terminal Alkynes, Sulfonyl Azides, and Thionoesters
-
A sequential procedure for the synthesis of 2,5-disubstituted thiazoles from terminal alkynes, sulfonyl azides, and thionoesters is reported. A copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1-sulfonyl-1,2,3-triazoles, which then react with thionoesters in the presence of a rhodium(II) catalyst. The resulting 3-sulfonyl-4-thiazolines subsequently aromatize into the corresponding 2,5-disubstituted thiazoles by elimination of the sulfonyl group. (Chemical Equation Presented).
- Miura, Tomoya,Funakoshi, Yuuta,Fujimoto, Yoshikazu,Nakahashi, Junki,Murakami, Masahiro
-
supporting information
p. 2454 - 2457
(2015/05/27)
-
- Programmed synthesis of arylthiazoles through sequential C-H couplings
-
A programmed synthesis of privileged arylthiazoles via sequential C-H couplings catalyzed by palladium or nickel catalysts has been accomplished. This versatile protocol can supply all possible arylthiazole substitution patterns (2-aryl, 4-aryl, 5-aryl, 2
- Tani, Satoshi,Uehara, Takahiro N.,Yamaguchi, Junichiro,Itami, Kenichiro
-
p. 123 - 135
(2014/01/06)
-
- Pd nanoparticle-silica nanotubes (Pd@SNTs) as an efficient catalyst for Suzuki-Miyaura coupling and sp2 C-H arylation in water
-
Silica nanotubes (SNTs) functionalized with Pd-NPs on the inner surface performed as efficient nano-reactors for C-C coupling in water; the nano-confinement offers minimized leaching of Pd and yet efficient mass transfer for Suzuki-Miyaura coupling and C-H arylation of thiazoles in water with very high TON.
- Park, Ginam,Lee, Sanghee,Son, Sang Jun,Shin, Seunghoon
-
supporting information
p. 3468 - 3473
(2013/12/04)
-
- Reigoselective arylation of thiazole derivatives at 5-position via Pd catalysis under ligand-free conditions
-
An efficient regioselective arylation of thiazole derivatives via Pd-catalyzed C-H activation is reported. The transformation was hypothesized through a Pd(0/II) catalytic cycle in the absence of special ligand sets. This method provided an efficient proc
- Liu, Xiang-Wei,Shi, Jiang-Ling,Yan, Jia-Xuan,Wei, Jiang-Bo,Peng, Kun,Dai, Le,Li, Chen-Guang,Wang, Bi-Qin,Shi, Zhang-Jie
-
supporting information
p. 5774 - 5777
(2013/12/04)
-
- Factors controlling the reactivity of heteroarenes in direct arylation with arylpalladium acetate complexes
-
The palladium-catalyzed direct arylation of heteroarenes with aryl halides has emerged as a viable alternative to conventional cross-coupling reactions. This paper reports a detailed mechanistic study on factors controlling the reactivity of heteroarenes in direct arylation with well-defined models of the presumed intermediate [PdAr(O2CMe-κ2O)L] (1). Although recent theoretical studies have provided a reasonable description of the mechanism of C-H bond cleavage by 1, its model compounds so far tested have been evidently less reactive than that expected. We found that [PdPh(O 2CMe-κ2O)(PPh3)] (1a) and [Pd(2,6-Me 2C6H3)(O2CMe-κ2O) (PPh3)] (1c), generated in situ from isolated [PdPh(μ-O 2CMe)(PPh3)]2 (4a) and [Pd(2,6-Me 2C6H3)(μ-O2CMe)(PPh 3)]4 (4c), respectively, react with a variety of heteroarenes in almost quantitative yields. The reactivity order of heteroarenes was evaluated by competitive reactions, showing that benzothiazole (8) is significantly less reactive than 2-methylthiophene (6), despite the acidity of 8 (pKa = 27) being much higher than that of 6 (pKa = 42). This reason was examined by kinetic experiments using 1c as well as DFT calculations using the model compound [PdPh(O2CMe- κ2O)(PH3)] (1d). Both heteroarenes reacted with 1 via a sequence of three elementary processes (i.e., substrate coordination, C-H bond cleavage, and C-C reductive elimination), but their energy profiles were significantly different from each other. The reaction of 6 obeyed simple second-order kinetics, and the deuterium-labeling experiments and DFT calculations indicated the occurrence of rate-determining reductive elimination. On the other hand, the reaction of 8 displayed saturation kinetics due to the occurrence of relatively stable coordination of 8 prior to C-H bond cleavage. This coordination stability enhances the activation barrier for C-H bond cleavage, thereby causing the modest reactivity of 8. Thus, although the previous mechanistic studies on direct arylation have been focused largely on the C-H bond cleavage process, not only the C-H bond cleavage but also the substrate coordination and C-C reductive elimination must be considered.
- Wakioka, Masayuki,Nakamura, Yuki,Hihara, Yoshihiro,Ozawa, Fumiyuki,Sakaki, Shigeyoshi
-
p. 4423 - 4430
(2013/09/02)
-
- Aryl-aryl coupling via palladium-catalyzed C-P/C-H bond cleavage
-
The first example of aryl-aryl coupling through palladium-catalyzed C-P/C-H bond cleavage with good functional group tolerance is disclosed. This work demonstrates the phosphines could be used as coupling partners in palladium-catalyzed aryl-aryl coupling
- Li, Ziyuan,Zhou, Haipin,Xu, Jinyi,Wu, Xiaoming,Yao, Hequan
-
supporting information
p. 3281 - 3286
(2013/04/24)
-
- Direct arylation of simple azoles catalyzed by 1,10-phenanthroline containing palladium complexes: An investigation of C4 arylation of azoles and the synthesis of triarylated azoles by sequential arylation
-
Direct triarylation and sequential triarylation reactions of simple azoles catalyzed by [Pd(phen)2]PF6 are described. Simple azoles, such as N-methylimidazole, thiazole, and oxazole, were observed to undergo triaryaltion reactions even at their C4 positions when treated with aryl iodides in the presence of [Pd(phen)2]PF6 as a catalyst and a stoichiometric amount of Cs2CO3 in DMA at 150 °C. Using excess amounts of azoles, selective C5 monoarylation was achieved by using the same catalytic system. Subsequent efforts demonstrated that C5 arylated azoles undergo exclusive C2 arylation using [Pd(phen)2]PF6 as the catalyst with galvinoxyl as an additive. Finally, unprecedented C4 arylation reactions of 2,5-diaryl-azoles occur by using the new catalytic system to give the corresponding triarylated products in good to excellent yields. The results of mechanistic studies suggest that the C2 arylation process takes place by way of an electrophilic aromatic substitution (SEAr) palladation pathway, while arylation reactions at the C4 position occur via a SEAr palladation and/or radical mechanism. Finally, a concise, three-step synthesis of the Tie-2 Tyrosine Kinase Inhibitor has been executed starting with commercially available N-methylimidazole by a route that employs the new sequential arylation process.
- Shibahara, Fumitoshi,Yamaguchi, Eiji,Murai, Toshiaki
-
experimental part
p. 2680 - 2693
(2011/06/20)
-
- Palladium/2,2′-bipyridyl/Ag2CO3 catalyst for C-H bond arylation of heteroarenes with haloarenes
-
A Pd/bipy-based catalytic system for the C-H bond arylation of heteroarenes with haloarenes is described. The complex PdBr2(bipy)·DMSO, whose structure was unambiguously determined by X-ray crystallography, turned out to be a general catalyst precursor for the process. The reaction is applicable to a range of electron-rich five-membered heteroarenes, such as thiophenes, thiazoles, benzofurans, and indoles.
- Yanagisawa, Shuichi,Itami, Kenichiro
-
experimental part
p. 4425 - 4430
(2011/08/06)
-
- Nickel-catalyzed C-H arylation of azoles with haloarenes: Scope, mechanism, and applications to the synthesis of bioactive molecules
-
Novel nickel-based catalytic systems for the C-H arylation of azoles with haloarenes and aryl triflates have been developed. We have established that Ni(OAc)2/bipy/LiOtBu serves as a general catalytic system for the coupling with aryl bromides and iodides as aryl electrophiles. For couplings with more challenging electrophiles, such as aryl chlorides and triflates, the Ni(OAc)2/dppf (dppf=1,1′-bis(diphenylphosphino)ferrocene) system was found to be effective. Thiazoles, benzothiazoles, oxazoles, benzoxazoles, and benzimidazoles can be used as the heteroarene coupling partner. Upon further investigation, we discovered a new protocol for the present coupling using Mg(OtBu)2 as a milder and less expensive alternative to LiOtBu. Attempts to reveal the mechanism of this nickel-catalyzed heterobiaryl coupling are also described. This newly developed methodology has been successfully applied to the syntheses of febuxostat (a xanthine oxidase inhibitor that is effective for the treatment of gout and hyperuricemia), tafamidis (effective for the treatment of TTR amyloid polyneuropathy), and texaline (a natural product having antitubercular activity). Copyright
- Yamamoto, Takuya,Muto, Kei,Komiyama, Masato,Canivet, Jerome,Yamaguchi, Junichiro,Itami, Kenichiro
-
experimental part
p. 10113 - 10122
(2011/10/08)
-
- Copper-catalyzed oxidative arylation of heteroarenes under mild conditions using dioxygen as the sole oxidant
-
Dioxy-gently does it! A new copper-catalyzed oxidative cross-coupling reaction between heteroarenes and arylboronic esters has been developed. Uniformly high yields are obtained by using dioxygen as the sole oxidant under mild conditions (see scheme). Copyright
- Yang, Fanzhi,Xu, Zhaoqing,Wang, Zhe,Yu, Zhengkun,Wang, Rui
-
experimental part
p. 6321 - 6325
(2011/08/06)
-
- Oxidative biaryl coupling of thiophenes and thiazoles with arylboronic acids through palladium catalysis: Otherwise difficult C4-selective C-H arylation enabled by boronic acids
-
(Chemical Equation Presented) It adds up to 4! Thiophenes and thiazoles can be arylated in the 4- rather than the expected 5-position in a new C-H functionalization reaction (see scheme; TEMPO: 2,2,6,6-tetramethylpiperidine-N- oxyl). The boronic acid proved to be the key to achieving the otherwise difficult C4 selectivity. The method was applied to a concise synthesis of a key pharmacological structure with potential for treatment of Alzheimers disease.
- Kirchberg, Sylvia,Tani, Satoshi,Ueda, Kirika,Yamaguchi, Junichiro,Studer, Armido,Itami, Kenichiro
-
p. 2387 - 2391
(2011/04/21)
-
- A guideline for the arylation of positions 4 and 5 of thiazole via Pd-catalyzed cross-coupling reactions
-
The arylation of thiazoles in 4- and 5-position was investigated in detail. Suzuki-Miyaura and Stille cross-coupling reactions were tested using thiazoles either as halide or organometal species. The obtained results were critically compared to develop he
- H?mmerle, Johanna,Schnürch, Michael,Iqbal, Naseer,Mihovilovic, Marko D.,Stanetty, Peter
-
experimental part
p. 8051 - 8059
(2010/10/21)
-
- A systematic study of Suzuki-Miyaura cross-coupling reactions on thiazoleboronic esters in the 4- and 5-position
-
A systematic study of the Suzuki-Miyaura cross-coupling reaction of thiazoleboronic esters under microwave conditions is presented. Boronic acid esters were prepared in the 4- and 5-position of the thiazole ring and subsequently cross-coupled with a number of different (hetero)aryl halides. Yields of the coupling process depended on the reactivity of the boronic acid at the particular position in the thiazole system, as hydrolysis and subsequent deboronation was found to be a major side reaction. Georg Thieme Verlag Stuttgart.
- Schnuerch, Michael,Haemmerle, Johanna,Mihovilovic, Marko D.,Stanetty, Peter
-
experimental part
p. 837 - 843
(2010/09/18)
-
- Catalyst-controlled regioselective suzuki couplings at both positions of dihaloimidazoles, dihalooxazoles, and dihalothiazoles
-
(Chemical Equation Presentation) Various dihaloazoles can be monoarylated at a single C-X bond with high selectivity via Suzuki coupling. By changing the palladium catalyst employed, the selectivity can be switched for some dihaloazoles, allowing for Suzuki coupling at the other, traditionally less reactive C-X bond. These conditions are applicable to coupling of a wide variety of aryl-, heteroaryl-, cyclopropyl-, and vinylboronic acids with high selectivities and enable the rapid construction of diverse arrays of diarylazoles in a modular fashion.
- Strotman, Neil A.,Chobanian, Harry R.,He, Jiafang,Guo, Yan,Dormer, Peter G.,Jones, Christina M.,Steves, Janelle E.
-
supporting information; experimental part
p. 1733 - 1739
(2010/05/18)
-
- COPPER-CATALYZED C-H BOND ARYLATION
-
The present invention is a one-step method for efficiently converting carbon-hydrogen bonds into carbon-carbon bonds using a combination of aryl halides, a substrate, and a copper salt as catalyst. This method allows faster introduction of complex molecular entities, a process that would otherwise require many more steps. This invention is particularly relevant for the organic synthesis of complex molecules such as, but not limited to, pharmacophores and explosives.
- -
-
Page/Page column 17
(2009/04/24)
-
- A comparative study on stille cross-coupling reactions of 2-phenylthiazoles and 2-phenyloxazoles
-
A systematic study of the cross-coupling capability of the 4- and 5-positions of 2-phenylthiazoles and -oxazoles under Stille conditions is presented. The azoles were both applied as stannanes and as the halide component. The obtained results were compared regarding the position of the halide and Bu3Sn group. In order to establish a general reactivity platform for those heterocyclic systems, a broad variety of aromatic and heteroaromatic halides were coupled and some significant differences concerning the coupling properties of the investigated systems were observed. Georg Thieme Verlag Stuttgart.
- Haemmerle, Johanna,Spina, Markus,Schnuerch, Michael,Mihovilovic, Marko D.,Stanetty, Peter
-
experimental part
p. 3099 - 3107
(2009/04/06)
-
- Copper-catalyzed arylation of heterocycle C-H bonds
-
A new method for the direct, copper-catalyzed arylation of heterocycle C-H bonds by aryl halides has been developed. In addition to electron-rich five-membered heterocycles, electron-poor pyridine oxides can also be arylated. The best results are obtained by using a combination of lithium tert-butoxide base, aryl iodide coupling partner, and copper iodide catalyst. Copyright
- Do, Hien-Quang,Daugulis, Olafs
-
p. 12404 - 12405
(2008/09/17)
-
- Direct arylation of thiazoles on water
-
Wetter is better: The direct arylation of thiazoles on water is quicker, cleaner, and higher-yielding than arylation in organic solvents. The reaction works under mild conditions for an array of aryl iodides, producing 2,5-diaryl thiazoles in excellent yields. Importantly, novel bi-heteroaryl compounds are produced without the requirement for stoichiometric organometallic coupling agents. (Figure Presented).
- Turner, Gemma L.,Morris, James A.,Greaney, Michael F.
-
p. 7996 - 8000
(2008/09/17)
-
- Comparing the reactivity of the 4- and 5-positions of 2-phenylthiazoles in stille cross-coupling reactions
-
A systematic study of the cross-coupling capability of 4-and 5-substituted 2-phenylthiazoles under Stille conditions is presented. Two cross-coupling options were investigated: 1) combination of thiazolylstannanes with various aryl(hetaryl) halides and, 2) reaction of halothiazoles with PhSn(Bu) 3 as coupling partner. The results obtained from the cross-coupling reactions on the 4- and 5-positions of the thiazole system were compared regarding the influence of the position of the halide (Br, I) and the Bu 3Sn group on both coupling partners. A broad selection of aromatic and heteroaromatic halides was coupled in order to establish a general reactivity platform for this heterocyclic system. Georg Thieme Verlag Stuttgart.
- H?mmerle, Johanna,Schnürch, Michael,Stanetty, Peter
-
p. 2975 - 2978
(2008/03/12)
-
- Cobalt-catalyzed arylation of azole heteroarenes via direct C-H bond functionalization
-
(Equation presented) We herein report a new cobalt-catalyzed method for arylation of azole heteroarenes, including thiazole, oxazole, imidazole, benzothiazole, benzoxazole, and benzimidazole. The direct arylation of thiazole and oxazole was achieved both with iodo- and bromoarenes as the aryl donors in the presence of cobalt catalyst [Co(OAc)2/IMes] and cesium carbonate, while imidazole required the use of zinc oxide as the base. A complete reversal of arylation from C-5 to C-2 was accomplished using the bimetallic Co/Cu/IMes system. A direct comparison of the new cobalt method and the previously developed palladium protocol revealed significant differences, in terms of both chemical yield and selectivity.
- Sezen, Bengue,Sames, Dalibor
-
p. 3607 - 3610
(2007/10/03)
-
- Palladium-catalyzed direct arylation of thiazoles with aryl bromides
-
Thiazole, 2-phenyl or -alkyl substituted one and benzothiazole are efficiently arylated with aryl bromides at the 2- and/or 5-position(s) in the presence of Pd(OAc)2 and a bulky phosphine ligand using Cs2CO3 as base. 2-Phenyl-5-thiazolecarboxanilide undergoes successive diarylation at the 4- and 5-positions accompanied by decarbamoylation.
- Yokooji, Aya,Okazawa, Toru,Satoh, Tetsuya,Miura, Masahiro,Nomura, Masakatsu
-
p. 5685 - 5689
(2007/10/03)
-
- Regiocontrolled Synthesis of Substituted Thiazoles
-
(Formula Presented) The regiocontrolled synthesis of 2,5-disubstituted and 2,4,5-trisubstituted thiazoles from ethyl 2-bromo-5-chloro-4-thiazolecarboxylate 1 using sequential palladium-catalyzed coupling reactions is described.
- Hodgetts, Kevin J.,Kershaw, Mark T.
-
p. 1363 - 1365
(2007/10/03)
-
- Thionation of ω-acylamino ketones with Lawesson's reagent: Convenient synthesis of 1,3-thiazoles and 4H-1,3-thiazines
-
The reaction of ω-acylamino ketones with Lawesson's reagent (=2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide; LR) is described. Treatment of 2-acylamino ketones 1 (n = 0) with LR gave 1,3-thiazole derivatives 3 in good yields (Scheme 1
- Nishio, Takehiko,Ori, Mayuko
-
p. 2347 - 2354
(2007/10/03)
-
- Palladium-Catalyzed Arylation of Azole Compounds with Aryl Halides in the Presence of Alkali Metal Carbonates and the Use of Copper Iodide in the Reaction
-
The reactions of iodobenzene with azole compounds, 1,2-disubstituted imidazoles and 2-substituted oxazoles and thiazoles, were examined in the presence of catalytic amounts of Pd(OAc)2 and PPh3 in DMF using alkali metal carbonates as bases. It was found that the coupling products, 5-arylazoles, could be selectively produced in good yields by using CS2CO3. In the case that their 2-position is unsubstituted, the site could also be arylated. In reactions using bromobenzene in place of iodobenzene, K2CO3 was also as effective as Cs2CO3- The addition of a stoichiometric amount of Cul appeared to specifically promote the reactions of thiazoles as well as those of thiophene derivatives. The reactions of 2-unsubstituted azole compounds with aryl iodides could be mediated by Cul to some extent without using the palladium species to give 2-arylazoles.
- Pivsa-Art, Sommai,Satoh, Tetsuya,Kawamura, Yoshiki,Miura, Masahiro,Nomura, Masakatsu
-
p. 467 - 473
(2007/10/03)
-
- SYNTHESIS OF SUBSTITUTED AZOL-4-YLPHOSPHONIUM SALTS FROM UNSATURATED AZLACTONES
-
Accessible unsaturated azlactones by successive treatments with water, chlorine, and triphenylphosphine provide valuable reagents containing the chracteristic >C=C(NHCOR)P+ group, which can be used for the synthesis of substituted oxazol(thiazol, selenazol)-4-ylphosphonium salts.The structure of these cyclization products correlates well with IR and PMR data, and is also reliably confirmed by the alkaline splitting of the C-P bond, leading in some cases to known derivatives of the corresponding 1,3-azoles.
- Brovarets, V. S.,Vydzhak, R. N.,Vinogradova, T. K.,Drach, B. S.
-
-
- ADDITION REACTION OF SULFUR DICHLORIDE TO FUNCTIONALIZED IMINES DIRECTED TOWARD HETEROCYCLIC SYNTHESIS
-
Although it was shown that the reactions of sulfur dichloride (SCl2) with imines 1a-c or with the azine 14 gave rise to very unstable 1:1 adducts, 1-aza- and 2-azabutadienes, 5 and 10, reacted with SCl2 to afford the isothiazoles 6 and the thiazoles 11, respectively, in high yields.Addition of SCl2 to heterocumulenes was also studied and the ketenimines 16 and diphenylketene 27 gave 1:1 adducts which were applied to heterocyclic synthesis as bifunctional reagents.Addition of SCl2 to these compounds was investigated by monitoring the reactions by 13C nmr spectroscopy.
- Komatsu, Mitsuo,Harada, Nobuyuki,Kashiwagi, Hiroshi,Ohshiro, Yoshiki,Agawa, Toshio
-
p. 119 - 134
(2007/10/02)
-
- Method of controlling insects and acarids with certain aryl-substituted thiazoles
-
The use of di- and triaryl-substituted thiazoles as pesticides is disclosed. Insects, such as mosquitos, and acarids, such as mites and ticks, are among the pests which may be controlled.
- -
-
-