- Tuning the Reactivity of Cofacial Porphyrin Prisms for Oxygen Reduction Using Modular Building Blocks
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We assembled eight cofacial porphyrin prisms using MTPyP (M = Co(II) or Zn(II), TPyP = 4-tetrapyridylporphyrin) and functionalized ruthenium-based "molecular clips"using coordination-driven self-assembly. Our approach allows for the rapid synthesis of these architectures in isolated yields as high as 98% for the assembly step. Structural and reactivity studies provided a deeper understanding of the role of the building blocks on the oxygen reduction reaction (ORR). Catalytic efficacy was probed by using cyclic and hydrodynamic voltammetry on heterogeneous catalyst inks in aqueous media. The reported prisms showed outstanding selectivity (>98%) for the kinetically hindered 4e-/4H+ reduction of O2 to H2O over the kinetically more accessible 2e-/2H+ reduction to H2O2. Furthermore, we have demonstrated significant cofacial enhancement in the observed catalytic rate constant ks (μ5 orders of magnitude) over the mononuclear analogue. We conclude that the steric bulk of the clip plays an important role in the structural dynamics of these prisms, which in turn modulates the ORR reactivity with respect to selectivity and kinetics.
- Crawley, Matthew R.,Zhang, Daoyang,Oldacre, Amanda N.,Beavers, Christine M.,Friedman, Alan E.,Cook, Timothy R.
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supporting information
p. 1098 - 1106
(2021/02/03)
-
- Visible-light-induced direct construction of amide bond from carboxylic acids with amines in aqueous solution
-
A novel visible-light-promoted N-acylation for the synthesis of amides from easily available carboxylic acids with amines in the presence of I2 within 2.5 h in aqueous solution has been developed. Using sunlight as the visible light source greatly reduces the cost of experiments and produces almost no toxic effects. Hence, this study provides an alternative catalytic system for the construction of a wide range of amides with readily available materials. Moreover, the strategy was successfully applied in the preparation of N-(3-(2,6-dimethoxyphenoxy)-7-nitroquinoxalin-2-yl)benzohydrazide, which displayed a signification anti-proliferation effect on A549, MCF-7 and HCT116 cell lines.
- Wang, Jin,Hou, Huiqing,Hu, Yongzhi,Lin, Jin,Wu, Min,Zheng, Zhiqiang,Xu, Xiuzhi
-
supporting information
(2021/02/09)
-
- Copper-Catalyzed Ullmann-Type Coupling and Decarboxylation Cascade of Arylhalides with Malonates to Access α-Aryl Esters
-
We have developed a high-efficiency and practical Cu-catalyzed cross-coupling to directly construct versatile α-aryl-esters by utilizing readily available aryl bromides (or chlorides) and malonates. These gram-scale approaches occur with turnovers of up to 1560 and are smoothly conducted by the usage of a low catalyst loading, a new available ligand, and a green solvent. A variety of functional groups are tolerated, and the application occurs with α-aryl-esters to access nonsteroidal anti-inflammatory drugs (NSAIDs) on the gram scale.
- Chen, Fen-Er,Chen, Tao,Cheng, Fei,Huang, Yin-Qiu,Li, Jia-Wei,Xiao, Xiao,Zhou, Chen
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supporting information
(2022/01/04)
-
- Synthesis of oxalamides by acceptorless dehydrogenative coupling of ethylene glycol and amines and the reverse hydrogenation catalyzed by ruthenium
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A sustainable, new synthesis of oxalamides, by acceptorless dehydrogenative coupling of ethylene glycol with amines, generating H2, homogeneously catalyzed by a ruthenium pincer complex, is presented. The reverse hydrogenation reaction is also accomplished using the same catalyst. A plausible reaction mechanism is proposed based on stoichiometric reactions, NMR studies, X-ray crystallography as well as observation of plausible intermediates.
- Ben-David, Yehoshoa,Diskin-Posner, Yael,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
-
p. 7188 - 7193
(2020/07/23)
-
- Theoretical and Experimental Studies: Cu(I)/Cu(II) Catalytic Cycle in CuI/Oxalamide-Promoted C-N Bond Formation
-
In modern Ullmann-Goldberg reactions, cheaper aryl chlorides are poor substrates. Recently, attention has been paid to facile CuI/oxalamide-promoted arylation of heteroatoms (N, O, and S) using cheaper aryl chlorides. However, the mechanism of the reaction and the role of oxalamides have not yet been investigated. In the present investigation, theoretical (density functional theory) and supporting in situ 1H NMR spectroscopy, UV-vis spectroscopy, Fourier transform infrared spectroscopy, and cyclic voltammetry studies have been performed to provide insight into the various aspects of the mechanism. Five different possible pathways have been investigated. [LCu(NHNu)] is the active copper catalytic species, in which L (oxalamide) coordinates Cu(I) through both C=O groups. Our studies show that the reaction follows an outer-sphere single-electron transfer pathway. Moreover, these studies also address the reason for the deactivation of a copper catalyst.
- Morarji, Devita V.,Gurjar, Kamlesh K.
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supporting information
(2019/07/03)
-
- Preparation method of oxamide
-
The invention provides a preparation method of oxamide. The preparation method comprises the following steps: an intermediate oxamide derivative is prepared from CO, O2 and amine compounds as raw materials by oxidation and carbonylation under the action of a catalyst 1, and then, oxamide is prepared through aminolysis of the oxamide derivative under the action of a catalyst 2. A novel method is used for coproducing oxamide and the oxamide derivative, and the problems that oxalate synthesis materials are poisonous, catalyst efficiency is low and the like in the original technology for synthesizing oxamide through aminolysis of oxalate are solved. Besides, the technologically synthesized oxamide derivative has good substrate applicability and can be applied to fields of medicine, pesticides,synthetic ligands, food additives and the like.
- -
-
Paragraph 0062; 0063; 0070; 0071; 0088
(2019/08/03)
-
- DIKETOPYRROLOPYRROLE PIGMENT COMPOSITION AND COLORING COMPOSITION BASED ON THAT DIKETOPYRROLOPYRROLE PIGMENT COMPOSITION
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PROBLEM TO BE SOLVED: To provide: a diketopyrrolopyrrole pigment composition allowing control of the color tone more economically and freely; and a coloring composition based on the diketopyrrolopyrrole pigment composition. SOLUTION: A diketopyrrolopyrrole pigment composition comprises a diketopyrrolopyrrole pigment represented by general formula (1) and an aromatic amide compound represented by general formula (2). In the diketopyrrolopyrrole pigment composition, the diketopyrrolopyrrole pigment may be represented by general formula (3). SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2019,JPOandINPIT
- -
-
Paragraph 0116; 0117
(2018/11/22)
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- Palladium-Catalyzed Modular Synthesis of Substituted Piperazines and Related Nitrogen Heterocycles
-
We report here a novel method for the modular synthesis of highly substituted piperazines and related bis-nitrogen heterocycles via a palladium-catalyzed cyclization reaction. The process couples two of the carbons of a propargyl unit with various diamine components to provide nitrogen heterocycles in generally good to excellent yields and high regio- and stereochemical control. (Chemical Equation Presented).
- Montgomery, Thomas D.,Rawal, Viresh H.
-
supporting information
p. 740 - 743
(2016/03/01)
-
- Solvent free, highly chemoselective N and O-acylation on silica and silica magnesium oxide: A recyclable solid surface
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Silica or silica/magnesium oxide mixed surface mediates the N and O-acylation, benzoylation or sulfonylation of hosts of substrates under solvent free conditions at ambient temperature with high chemoselectivity.
- Ghosh, Pranab,Mandal, Amitava
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p. 261 - 268
(2012/10/29)
-
- ZnO nanofluid as a structure base catalyst for chemoselective amidation of aliphatic carboxylic acids
-
ZnO nanofluids were synthesized and utilized as a new reaction media in the preparation of amides via direct amidation of aliphatic carboxylic acids with primary amines under solvent-free conditions. High yields and good selectivity are achieved with this psudo-homogeneous catalyst, while the recovered nanoZnO was reusable.
- Tamaddon, Fatemeh,Aboee, Fatemeh,Nasiri, Alireza
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experimental part
p. 194 - 197
(2012/02/04)
-
- Synthesis and structural investigations of Ni(II)- and Pd(II)-coordinated α-diimines with chlorinated backbones
-
Novel square planar Pd(II) α-diimines [PdX2{ArN{double bond, long}C(Cl)}2], where Ar = C6H5, (2,6-Me2C6H3), (2,6-iPr2C6H3) and X = Cl or Br, and the octahedral Ni(II) complex [NiBr2{(C6H5)N{double bond, long}C(Cl)}2(THF)2] have been prepared and characterised by spectroscopic methods. For two of the Pd(II) complexes and the Ni(II) complex the crystal structures were determined by X-ray crystallography. A further insight into the geometry and electronic structure of [PdBr2{(2,6-Me2C6H3)N{double bond, long}C(Cl)}2] was gained using density functional theoretical calculations (DFT). This compound resembles structurally and electronically typical olefin polymerisation pre-catalysts supported by α-diimines incorporating methyl- and 1,8-naphtalenyl substituents at the ligand backbone. The chlorine-substituted backbone of the free ligand [2,6-Me2C6H3N{double bond, long}C(Cl)]2 can be employed in further alkylation reactions to generate new multifunctional ligand prototypes with potential uses as ansa-metallocene/diimines building blocks for catalytic applications of heterobimetallic complexes.
- Pascu, Sofia I.,Balazs, Gabor,Green, Jennifer C.,Green, Malcolm L.H.,Vei, Ino C.,Warren, John E.,Windsor, Caroline
-
body text
p. 1157 - 1172
(2010/06/18)
-
- A new synthesis of bis-enaminones via acylation of ketones
-
A short and efficient synthesis for a series of 1,6-diaryl-3,4- diarylaminohexa-2,4-diene-1,6-diones was developed. Based on the acylation-prototropism sequence during the reaction of various aryl methyl ketones with bis-imidoyl chlorides, the products were isolated in good yields. Substituted acetophenones, acetylthiophene, 3-acetylpyridine, and acetylferrocene can be integrated into this reaction as ketone component. Similarly, α-tetralone can be transformed with bis-electrophiles into the corresponding bis-enaminones. Treatment of 2-acetylpyridine with N,N′-bis(4-tolyl)ethanebis(imidoyl) dichloride yielded not only the expected bis-enaminone, but also a new quinolizine derivative which was structurally characterized by single crystal X-ray analysis. Analogously, pinacolone and cyclopropyl methyl ketone can readily be converted into bis-enaminones. Monoimidoyl chlorides showed the same reactivity, providing derivatives in high yields. Georg Thieme Verlag Stuttgart.
- Buehrdel, Gunther,Beckert, Rainer,Petrlikova, Eva,Herzigova, Petra,Klimesova, Vera,Fleischhauer, Jan,Goerls, Helmar
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experimental part
p. 3071 - 3080
(2009/04/06)
-
- New osmium-based reagent for the dihydroxylation of alkenes
-
The cis dihydroxylation of alkenes is most efficiently accomplished by reaction with osmium tetroxide. Recently, the expense and toxicity of osmium tetroxide have led to a number of attempts to harness alternative osmium-based reagents, including microencapsulation and solid support techniques. We describe here the development of a new nonvolatile, stable, and recoverable osmium-based reagent devised for the stoichiometric cis dihydroxylation of alkenes. Although attempts to make this new dihydroxylation work with catalytic amounts of this reagent were unsuccessful, we did develop a sensitive test for free osmium tetroxide leached from the reagent in situ: this test may well have uses in probing future applications of derivatized osmium reagents.
- Donohoe, Timothy J.,Harris, Robert M.,Butterworth, Sam,Burrows, Jeremy N.,Cowley, Andrew,Parker, Jeremy S.
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p. 4481 - 4489
(2015/09/24)
-
- Method for the synthesis of amides and related products from esters or ester-like compounds
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A versatile, eco-friendly, and efficient method for the convenient conversion of esters and ester-like compounds into amides, peptides, carbamates, ureas, oxamides, oxamates, hydrazides, oxazolidinones, pyrazolones, oxazolidinediones, barbituric acids, and other molecules containing one or more OCN moieties in the presence of a diol or polyol is disclosed.
- -
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Page/Page column 9
(2008/06/13)
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- A new class of near-infrared electrochromic oxamide-based dinuclear ruthenium complexes
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(Chemical equation presented) We report the synthesis of a new class of symmetric and unsymmetric oxamide-based dinuclear ruthenium complexes. These complexes were characterized by NMR, ESI-MS, and electrochemical methods. Spectroelectrochemical analysis of the complexes showed broad absorptions in the NIR region for the mixed-valence state of the complexes. The introduction of a chiral group into the bridging ligand produced an optically active complex that was studied using circular dichroism.
- Rastegar, Majid F.,Todd, Erin K.,Tang, Hongding,Wang, Zhi Yuan
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p. 4519 - 4522
(2007/10/03)
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- Modifying Electronic Communication in Dimolybdenum Units by Linkage Isomers of Bridged Oxamidate Dianions
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Reactions of Mo2(O2CCH3)(DAniF) 3, DAniF = N, N′-di-p-anisylformamidinate, with oxamidate dianions [ArNC(O)C(O)NAr]2-, Ar = C6H5 and p-anisyl, give pairs of isomeric compounds where the [Mo2] units are bridged by the oxamidate anions. For the α isomers, the C-C unit of the dianion is nearly perpendicular to the Mo-Mo bonds, and these are essentially perpendicular to each other. For the β isomers, the corresponding C-C unit and the Mo-Mo bonds are essentially parallel to each other. Each type of isomer is stable in solution. The electronic communication as measured by the ΔE1/2 for the oxidation of each of the Mo2 units is significantly better for the β isomers. This is supported also by the appearance of what is conventionally called an intervalence charge-transfer band in the near infrared region upon oxidation of the β isomers but not the α isomers. Molecular mechanics and DFT calculations help explain the relative conformations in the α isomers and the relative energy differences between the α and β isomers.
- Cotton, F. Albert,Liu, Chun Y.,Murillo, Carlos A.,Villagran, Dino,Wang, Xiaoping
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p. 13564 - 13575
(2007/10/03)
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- Diamines having a C2 symmetry. Synthesis and application as ligands in the hydrogenation of prochiral substrates over rhodium complexes
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Chiral diamines having a C2 symmetry, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane and (5S,5′ S)-2,2,2′,2′-tetramethyl-3,3′-diphenyl-5,5′ -bioxazolidine, were synthesized on the basis of (+)-(2R,3R)-tartaric acid. Their structure was proved by X-ray analysis. The products were used as ligands in rhodium catalyst for enantioselective hydrogenation of α -acetamidocinnamic and itaconic acids.
- Shainyan,Ustinov,Bel'skii,Nindakova
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p. 104 - 110
(2007/10/03)
-
- Improved procedure for N-formylation of amines to formamides using formic acid, oxalyl chloride and imidazole
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The reaction of imidazole (15) with formyl chloride (14), generated in situ by the action of oxalyl chloride (10) on formic acid (3), afforded N-formylimidazole (7), which is a convenient formylating reagent. This procedure was used to prepare N-formyl derivatives (2) of aliphatic, aromatic and heteroaromatic amines (1) under mild conditions.
- Kitagawa,Ito,Tsutsui
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p. 1931 - 1934
(2007/10/02)
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- Novel syntheses of oxamides, oxamates and oxalates from diisopropenyl oxalate
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Diisopropenyl oxalate, obtained by catalytic addition of oxalic acid to propyne, is a useful reagent for the access to a variety of α-dicarbonyl compounds such as oxamides, oxamates and oxalates, under very mild conditions.
- Neveux, Muriel,Bruneau, Christian,Lecolier, Serge,Dixneuf, Pierre H.
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p. 2629 - 2640
(2007/10/02)
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- 1H, 13C, 15N, 2D and Variable Temperature NMR Study of the Role of Hydrogen Bonding in the Structure and Conformation of Oxamide Derivatives
-
The structure and conformation of N,N'-bisoxamide (1); N,N'-bisoxamide (2); N,N'-bis(phenyl)oxamide (3); N,N'-bisoxamide (4); N,N'-bisoxamide (5); N-methylamide (6); N-methylamide (7); N-phenylmethylamide (8); N-methylamide (9) and N-methylamide (10) were unambiguously established by 1H, 13C, 15N, 2D and variable temperature NMR spectroscopy.A careful NMR investigation of the conformational behaviour in these systems was relevant.It has been found that the dicarbonylic group in compounds 1-5 has a trans geometry, stabilized by intramolecular hydrogen bonding and that they possess a C2 axis.Compounds 1 and 2 are planar and compounds 1, 2, 4 and 5 present the amidic proton coordinated by two oxygen atoms.
- Martinez-Martinez, Francisco Javier,Ariza-Castolo, Armando,Tlahuext, Hugo,Tlahuextl, Margarita,Contreras, Rosalinda
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p. 1481 - 1485
(2007/10/02)
-
- Heterocycles from Heterocycles. 1,3-Diaryl-4,5-imidazolidinediones from 1,3,5-Triarylhexahydro-1,3,5-triazines and Oxalyl Chloride
-
1,3-Diaryl-4,5-imidazolidinediones (6) are easily synthesized from 1,3,5-triarylhexahydro-1,3,5-triazines (1) and oxalyl chloride (5) in a reaction not likely to involve the zwitterionic intermediate (3) of the N-methylenearylamine dimer, but viewing the sequential pick up of two units of the monomer (2) by oxalyl chloride (5).The essential role of ethyl alcohol added to the reaction mixture is recognized.Reaction conditions have been optimized and some ten imidazolidinediones (6) were prepared in good to excellent yields.Geometric parameters of 6 were obtained by X-ray diffraction analysis: all the nuclei are found almost in one plane except for a small twist of the phenyl rings about the C-N bond.
- Verardo, Giancarlo,Giumanini, Angelo G.,Gorassini, Fausto,Tolazzi, Marilena,Strazzolini, Paolo
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p. 10609 - 10628
(2007/10/02)
-
- Preparations of carboxylic acid esters containing heptafluoroisopropyl groups
-
The reaction of fluoroglyoxylic acid esters and fluoroformic acid esters with perfluoropropene (PFP) yielded perfluoro(3-methyl-2-oxobutyric) acid esters and perfluoroisobutyric acid esters, respectively.Oxamide derivatives and 2,3-quinoxalinediol have been prepared by the reaction of perfluoro(3-methyl-2-oxobutyric) acid esters with amines and o-phenylenediamine, respectively.Perfluoro(3-methyl-2-oxobutyric) acid esters give perfluoroisobutyric acid esters on heating in the presence of fluoride ion in an aprotic solvent.
- Suyama, T.,Kato, S.,Mizutani, Y.
-
-
- A convenient one-pot synthesis of symmetric secondary and tertiary vicinal diamines
-
A convenient one-pot synthesis of symmetric vicinal diamines utilizing sodium borohydride/trifluoroacetic acid reduction methodology is described.
- Nutaitis
-
p. 1081 - 1085
(2007/10/02)
-
- SmI2 Promoted Coupling Reaction of Isocyanates to Oxamides
-
Oxamides were obtained in moderate to good yields by the reaction of isocyanates with the SmI2/HMPA/THF system under mild conditions.The system also caused desulfurization of isothiocyanates to give isocyanides in good yields.
- Liu, Yun-Shan,Bei, Mei-Zhi,Zhou, Zhi-Hua,Takaki, Ken,Fujiwara, Yuzo
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p. 1143 - 1144
(2007/10/02)
-
- Method of preparation of oxalic acid esters and amides
-
A new process is described for the preparation of oxalic acid esters and amides of general formula (I) STR1 wherein Z designates an --OR or --NR1 R2 group, wherein R represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R1 is hydrogen or substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R2 represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, or R1 and R2 taken together with the adjacent nitrogen atom represent a saturated 5-, 6-, 7-, or 8-membered heterocyclic ring, which may contain an additional heteroatom selected from --O--, --S--, and --N(H, Alkyl)--, and optionally bear one or more alkyl or alkenyl substituents, and Z1 designates an --OR or --NR1 R2 group, wherein R, R1, and R2 are as defined before, or a group --NHCOCH3, which comprises the base-catalysed reaction of diacetyloxamide with an alcohol ROH or/and an amine HNR1 R2. The compounds of formula (I) have many industrial utilities, mainly as intermediates and stabilizers in the polymer field.
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-
-
- Neue Dimethinmerocyanin-Farbstoffe mit der (Sulfobutyl)benzothiazol-Gruppe als Donor-Teilchromophor und deren Aggregationsverhalten in waessriger Loesung
-
A series of novel dimethinemerocyanine dyes with the (sulfobutyl)benzothiazole group as the donor part of the chromophor is synthesized in good yield and their aggregation tendency in H2O without addition of salt investigated.The merocyanine dye 2b only gives J-aggregation in H2O.The dyes 1a-f and 2a exhibit an intense, red-shifted absorption band due to J-aggregation in H2O in the presence of Me4NCl.In contrast, the dyes 1g and 2c-f show a slightly red-shifted absorption band.The degree of aggregation in H2O is investigated by ultracentrifugation of the representative 2e.Indeed, the slightly red-shifted absorption band in H2O is due to aggregation of 'oligomers' of the dye.Contrary to the aggregation of 'polymers' of dyes (J-aggregation), we suggest the term 'K' band for the slightly red-shifted absorption band.The hemicyanine dye 5 gives the same absorption band in MeOH and in MeOH/H2O 1:3.The dye 11 shows an absorption band in H2O that is probably blue-shifted because of negative solvatochromism.The merocyanine dye 13 gives H-aggragation in H2O.
- Kussler, Manfred,Balli, Heinz
-
p. 295 - 306
(2007/10/02)
-
- Synthesis of 1,3-Disubstituted Diazolidines
-
Symmetrical and unsymmetrical 1,3-diaminoethanes 1 are obtained by the reduction of N,N'-disubstituted oxamides 4 with lithium aluminum hydride.The oxamides 4 are readily produced by treatment of diethyl oxalate with primary amines.The 1,3-diaminoethanes 1 lead to 1,3-diazolidines 2 on treatment with formaldehyde.
- Lambert, Joseph B.,Huseland, Dave E.,Wang, Gen-tai
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p. 657 - 658
(2007/10/02)
-
- Reaction of Phenyl Isothiocyanate with Some α,N-Acylamino and Dicarboxylic Acids
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Dianilides are obtained in the reaction of phenyl isothiocyanate with dicarboxylic acids, such as oxalic, malonic, glutaric and adipic acids, and not in the case of succinic and phthalic acids.In the case of succinic acid, the product is monoanilide, dianilide or N-phenylsuccinimide, depending upon the reaction conditions.Phthalic acid always gives N-phenylphthalimide.N-Acylamino acids on reaction with phenyl isothiocyanate yield the corresponding anilides.The probable mechanisms of this reaction are discussed.
- Ashare, Ram,Ram, Ram N.,Mukerjee, Arya K.
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p. 759 - 760
(2007/10/02)
-
- Photodegradation of Amino- and Hydroxyphenazone in Acetone
-
The photochemical degradation of aminophenazone in acetone leads to 2--4-oxohepta-2,5-dienoic anilide (9), N,N-dimethyl-N'-phenyl oxamide (10) and N,N-dimethyl-N'-phenylurea (11).In addition to the last two products, oxanilide and N-methyl-N'-phenyl oxamide are obtained, when the irradiation is carried out in acetonitrile. 6-Methyl-2--4-oxohepta-2,5-dienoic anilide, oxanilide and N-methyl-N'-phenyl oxamide are formed as a result of hydroxyphenazone photolysis in acetone.The degradation mechanism is discussed.
- Reisch, Johannes,Abdel-Khalek, Magdi
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p. 1000 - 1006
(2007/10/02)
-
- Oxidation of Enamine-esters with Lead Tetra-acetate. Part 2. Products from N-Aryl- and N-Benzyl-aminofumarates.
-
Dimethyl anilinofumarate and N-benzylaminofumarate are oxidised by lead tetra-acetate to pyrroline, pyrrolin-2-one and pyrrole derivatives.Some other N-arylaminofumarates give the corresponding oxanilates by autoxidative cleavage.
- Vernon, John M.,Carr, Richard M.,Sukari, Mohamed A.
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p. 1310 - 1334
(2007/10/02)
-
- Reaction Pathways for Arylcarbamoyl Radicals and the Cyclization of o-Substituted Phenylcarbamoyl Radicals
-
N-Arylcarbamoyl radicals generated from N-arylformamides with di-t-butyl peroxide (ButOOBut) in chlorobenzene at 110 deg C give rise to a series of reactions depending on the nature and the position of the substituent in the aromatic ring.When the aryl group is phenyl or p-chlorophenyl the following reactions on carbamoyl radicals occur: (i) loss of hydrogen with formation of aryl isocyanates, whereas the loss of carbon monoxide leads to arylamines via arylaminyl radicals; (ii) dimerization to NN'-diaryloxamides; (iii) aromatic substitution on chlorobenzene leading to N-arylbenzamides (ipso-substitution) and N-arylchlorobenzamides.The isocyanates trapped by t-butyl alcohol and arylamines give t-butyl N-arylcarbamates and NN'-diarylureas.With o-substituted N-phenylformamides intramolecular cyclization is observed as well; in fact, the N-(o-cyanophenyl)formamide affords isatin via addition of the carbamoyl radical to the cyano-group while the N-formamide gives 2-benzothiazolone and phenyl radicals through an SHi reaction on the sulphur atom; finally 2-formamidobiphenyls furnish phenanthridones in very high yields.
- Leardini, Rino,Tundo, Antonio,Zanardi, Giuseppe
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p. 3164 - 3167
(2007/10/02)
-
- Oxalyl Isothiocyanates and Carbonyl Halogenide Isothiocyanates
-
Preparations of ethoxalyl isothiocyanate (1), oxalyl diisothiocyanate (3), oxalyl chloride isothiocyanate (4), and oxalyl bromide isothiocyanate (16) are described.Thermal decarbonylation of 4 and 16 leads to carbonyl chloride isothiocyanate (7) and carbonyl bromide isothiocyanate (17), resp.Some reactions of the new oxalyl and carbonyl pseudohalogenides are given.Trichloromethyl isothiocyanate (13) is obtained from trichloromethyl isocyanide dichloride (12).
- Bunnenberg, Rolf,Jochims, Johannes C.
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p. 1746 - 1751
(2007/10/02)
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- Derivatives of 1,3,5-Triazine: Part III - Cyanuric Chloride-Dimethylformamide as a New Reagent for Synthesis of Amides, Esters, Aldehydes and for Dehydration Reactions
-
Cyanuric chloride reacts with dimethylformamide to form a complex (I), which can be used directly for the synthesis of amides, esters, relatively simple peptides, aldehydes and for dehydration reactions.
- Lahoti, R. J.,Wagle, D. R.
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p. 1007 - 1008
(2007/10/02)
-
- The Beckmann Reaction of Phenyl-substituted 1,3-Dioximes
-
The 1,3-diketones 1a - c react with hydroxylammonium choride to give isoxazolin-5-ols 2a - c predominantly, in addition to dioximes 3a and b, respectively.The anti (E,E) configuration of the dioximes was established by UV and 1H NMR.By Beckmann reaction of 3a, b and d, 4H-pyrazole N-oxides 4a, b and d were formed.The amphi (Z,E) configuration of 1,3-bis(hydroxyimino)-1,3-diphenyl-2-propanone (6) was established by 13C NMR.
- Gnichtel, Horst,Boehringer, Ulrich
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p. 1507 - 1513
(2007/10/02)
-
- The Reaction of N-Sulfinylamines with Isocyanides and Sythesis of 2,5-Diaryl-3,4-diarylimino-1,2,5-thiadiazolidin-S-oxides
-
N-Sulfinylamines 1 react with isocyanides 2 to give isocyanates 3, isothiocyanates 6, and especially 2,5-diaryl-3,4-diarylimino-1,2,5-thiadiazolidin-S-oxides 7.This new heterocyclic ring system 7 can also be sythesized in high yields by a cyclization reaction tetraarylated oxalic amidines 9 with thionyl chloride.The acid catalyzed hydrolysis of the heterocyclic compounds 7 leads to oxalic anilides 8, the hydrolysis with alkali forms amidines 9.The amidine 9a reacts with N-sulfinyl-p-toluenesulfonamide 11 to give an open chained adduct 12.
- Beckert, R.,Mayer, R.
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p. 273 - 280
(2007/10/02)
-
- Oxanilic acids, a new series of orally active antiallergic agents
-
A large number of oxanilic acid esters and N heteroaryl oxamic acid esters were prepared and found to have antiallergic activity using the rat passive cutaneous anaphylaxis (PCA) test. Many of the oxanilic acid esters are active orally, with the most active species having an aryl 2' carbamoyl group and a 3' methoxy group. Hydrolysis of the ester from the oxanilic ester moiety causes a loss of oral activity.
- Sellstedt,Guinosso,Begany,Bell,Rosenthale
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p. 926 - 933
(2007/10/05)
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