New N,S-Substituted Dienes from Mono(thio)substituted-2-nitrohalo-1,3-diene and Some Amines

Mono(thio)substituted nitrodiene compound 1 reacted with 2a–f and yielded 3a–f in methylene chloride. Compound 1 gave 7 by the reaction with 6. Compounds 5a–c were obtained by the reactions of 4a–c with 1. 3a also has been structurally characterized using single-crystal X-ray diffraction analyses.     

Synthesis of Some Novel S- and N,S-Substituted Chlorobutadienes

Abstract

Mono(thio)substituted nitrodienes were synthesized by reactions of 2-nitro-pentachloro-1,3-butadiene with some thiols [(tert-butylbenzyl)thio- and 2,3,5,6-tetra-fluorophenylthio-] either directly or in ethanol in the presence of sodium hydroxide. N,S-Substituted 1,3-butadienes were obtained from the reaction of the mono(thio)substituted nitrodienes with morpholine and some piperazine derivatives in dichloromethane. Also mono- and di(thio)substituted perchlorobutadienes were synthesized from the reactions of hexachloro-1,3-butadiene with o-aminothiophenol in ethanol in the presence of sodium hydroxide. The structures of the new compounds were characterized by microanalysis and spectroscopic data.     

New N,S-Substituted Dienes from the Reactions of Some Aliphatic Mono(thio)substituted Nitrodienes with Aromatic Primary Amines and Cyclic Amines

Reaction of 2-nitropentachlorobutadiene with thiols and amines gave new N,S- and S,S-substituted nitrodiene compounds is discussed.     

The Synthesis of Novel S-, S,S-, S,S,S-, and N,S-Substituted Nitrodienes from Polyhalonitrodienes and Thiols

Abstract

The novel S-, S,S-, and S,S,S-substituted nitrobutadienes were synthesized from the reactions of 2-nitrobutadiene compounds with some thiols. The new N,S-substituted nitrobutadienes were obtained from the reaction of the mono-thiosubstituted butadienes with morpholine, thiomorpholine, homopiperazine, and piperazine derivatives. The structures of new compounds were determined by spectroscopic techniques.

GRAPHICAL ABSTRACT      

Nucleophilic substitution in the series of (1,2,3-triazol-1-yl)-1,2,5-oxadiazoles. Reactions with N-, O-, and S-nucleophiles

Methods for the synthesis of amino(1,2,3-triazol-1-yl)-1,2,5-oxadiazoles (amino-triazolylfurazans) with CH₂Cl and COCH₂Br substituents in the triazole ring were developed and nucleophilic substitution for their halogen atom in reactions with N-, O-, and S-nucleophiles were studied. The possibility of displacing the NO₂ group from the furazan and triazole rings in triazolylfurazans by an azido group was investigated. Novel compounds of this series were synthesized; the reaction rate and pathway were found to depend on the nature of the substrate and the reagent and the position of the substituent in isomers. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1866–1876, August, 2005.     

Chemoselective Synthesis of Substituted Imines,Secondary Amines,and β‐Amino Carbonyl Compounds from Nitroaromatics through Cascade Reactions on Gold Catalysts

Substituted imines, α,β‐unsaturated imines, substituted secondary amines, and β‐amino carbonyl compounds have been synthesized by means of new cascade reactions with mono‐ or bifunctional gold‐based solid catalysts under mild reaction conditions. The related synthetic route involves the hydrogenation of a nitroaromatic compound in the presence of a second reactant such as an aldehyde, α,β‐unsaturated carbonyl compound, or alkyne, which circumvents an ex situ reduction process for producing the aromatic amine. The process is shown to be highly selective towards other competing groups, such as double bonds, carbonyls, halogens, nitriles, or cinnamates, and thereby allows the synthesis of different substituted nitrogenated compounds. For the preparation of imines, substituted anilines are formed and condensed in situ with aldehydes to provide the final product through two tandem reactions. High chemoselectivity is observed, for instance, when double bonds or halides are present within the reactants. In addition, we show that the Au/TiO₂ system is also able to catalyze the chemoselective hydrogenation of imines, so that secondary amines can be prepared directly through a three‐step cascade reaction by starting from nitroaromatic compounds and aldehydes. On the other hand, Au/TiO₂ can also be used as a bifunctional catalyst to obtain substituted β‐amino carbonyl compounds from nitroaromatics and α,β‐unsaturated carbonyl compounds. Whereas gold sites promote the in situ formation of anilines, the intrinsic acidity of Ti species on the support surface accelerates the subsequent Michael addition. Finally, two gold‐catalyzed reactions, that is, the hydrogenation of nitro groups and a hydroamination, have been coupled to synthesize additional substituted imines from nitroaromatic compounds and alkynes.     

Reactions of Hydrazonoyl Halides 33 1 : Synthesis of Some New 2,3-Dihydro-1,3,4-thiadiazoles Containing Pyrazol-3-yl,Indolin-2-one-2-yl and Indan-1,3-dione-2-yl Moieties

Some new 2,3-dihydro-1,3,4-thiadiazoles containing pyrazol-3-yl, indolin-2-one-2-yl and indan-1,3-dione-2-yl moieties in a good yields obtained from the reaction of hydrazonoyl halides with thiocarbamate and carbodithioate in ethanolic triethylamine respectively. In contrast, pyrazolylthiourea reacts with hydrazonoyl halides under the same condition afford corresponding hydrazonoyl sulfide derivatives.     

Synthesis of Functionalized Thiophenes by Four‐component Reactions of 1,3‐Thiazolidinedione,Aromatic Aldehydes,Cyanoacetamide and Cyclic Secondary Amines

The polysubstituted thiophene derivatives were conveniently prepared by the four‐component reactions of 1,3‐thiazolidinedione, aromatic aldehydes, cyanoacetamide and cyclic secondary amines such as pyrrolidine, morpholine and piperidine. The reaction mechanism is believed to involve domino reactions of Knoevenagel condensation, Michael addition, ring‐opening and recyclization of 1,3‐thiazolidinedione.     

Synthesis of functionalized 2-(arylthio)benzoates by formal [3+3] cyclizations of 3-arylthio-1-silyloxy-1,3-butadienes with 3-silyloxy-2-en-1-ones and 1,3-diacylcyclopropanes

Functionalized 2-(arylthio)benzoates are prepared by formal [3+3] cyclizations of 3-arylthio-1-trimethylsilyloxy-1,3-butadienes with 3-silyloxy-2-en-1-ones and 1,1-diacylcyclopropanes.     

Studies on Reactions of Cyclic Oxalyl Compounds with Hydrazines or Hydrazones. 2. Synthesis and Reactions of 4-Benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic Acid

4-Benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, obtained from the corresponding furan-2,3-dione and N-benzylidene-N'-(4-nitrophenyl)hydrazine, was converted via reactions of its acid chloride with various alcohols or N-nucleophiles into the corresponding ester or amide derivatives. The nitrile of the starting acid and 1-(4-aminophenyl)-4-benzoyl-5-phenyl-1H-pyrazole-3-carboxylic acid were also obtained. While cyclocondensation reactions of the two acids and the nitrile mentioned with hydrazines lead to pyrazolo[3,4-d]pyridazine derivatives, the reaction of starting acid with 2-hydrazinopyridine provided the hydrazonopyrazole acid derivative.     

Synthesis of 3,5-diaryl-4-chlorophthalates by [4+2] cycloaddition of 1-ethoxy-2-chloro-1,3-bis(trimethylsilyloxy)-1,3-diene with dimethyl acetylenedicarboxylate and subsequent site-selective Suzuki-Miyaura reactions

The [4+2] cycloaddition of 1-ethoxy-2-chloro-1,3-bis(trimethylsilyloxy)-1,3-diene with dimethyl acetylenedicarboxylate (DMAD) afforded dimethyl 4-chloro-3,5-dihydroxyphthalate. Site-selective Suzuki-Miyaura reactions of its bis(triflate) provide a convenient approach to 3,5-diaryl-4-chlorophthalates containing two different aryl groups.     

Synthesis of 4,5-dihydrothiazole derivatives by the reaction of perfluoro-2-methylpent-2-en-3-yl isothiocyanate with ambident N,O- and N,S-nucleophiles

The reactions of perfluoro-2-methylpent-2-en-3-yl isothiocyanate with ambident N,O- and N,S-nucleophiles (thiazole-2-thione, pyridine-2-thione, 2-hydroxypyridine, benzothiazole-2-thione, benzoxazole-2-thione, 3,4,5,6-tetrahydropyrimidine-2-thione) in the presence of triethylamine yield only 2-N-substituted 4,5-dihydrothiazole derivatives. The molecular structures of three products were determined by X-ray diffraction analysis. The reaction pathways are discussed.     

Investigation of 2,3'-Biquinolyl. 10. The Regioselectivity of the Reaction of 2,3'-Biquinolyl and 1'-Alkyl-3-(2-quinolyl)quinolinium Halides with Halo Derivatives in the Presence of Metallic Lithium and Magnesium

2,3'-Biquinolyl reacts with halo derivatives in the presence of metallic lithium to give addition products at position 4', treatment of which with water gives 4'-R-1',4'-dihydro-2,3'-biquinolyls and with halo derivatives gives 1'-alkyl-4'-R-1',4'-dihydro-2,3'-biquinolyls. The reaction of 2,3'-biquinolyl with halo derivatives in the presence of metallic magnesium gives a mixture of products of addition at positions 2' and 4'. 1-Alkyl-3-(2-quinolyl)quinolinium halides and halo derivatives with metallic magnesium give 1'-alkyl-2'-R-1',2'-dihydro-2,3'-biquinolyls but form a complex mixture of substances when metallic lithium is used.     

Regio- and Stereoselective Synthesis of γ-Alkylidenebutenolides by Cyclization of Dilithiated 1,3-Dicarbonyl Compounds with N,N′-Dimethoxy-N,N′-dimethylethane- diamide

The remarkably simple synthesis of γ-alkylidenebutenolides 3 is achieved by cyclization of the dilithiated 1,3-dicarbonyl compounds 1 with N,N′-dimethoxy-N,N′-dimethylethanediamide ( 2 ). This regio- and stereoselective cyclization provides a route to a wide range of butenolides, which are of pharmacological relevance and of importance for natural product synthesis.     

N,N-二甲酰基-α-氨基苯乙酮与芳醛的羟醛缩合反应及3-羟基-2-甲酰氨基-1,3-二苯基-1-丙酮的晶体结构

研究了N,N-二甲酰基-α氨基苯乙酮与芳醛的羟醛缩合反应,得到5种控醛缩合产物,并用X-射线单晶衍射法测定了3-羟基-2-甲酰氨基-1,3-二苯-1-丙酮的晶体和分子结构.晶体的空间群为P1;晶体学数据:a=10.802(2)A,b=11.088(2)A,c=14.395(3)A,α=68.20(1)°,β=69.19(1)°,γ=64.35(1)°;V=1403.7(0.5)(?);D_c=1.27 g/cm~(-3).Z=4.F(000)=567.92(e).μ(MoKa)=0.83cm~(-1)。     

Synthesis of Functionalized Pyrazoles via 1,3‐Dipolar Cycloaddition of α‐Diazo‐β‐ketophosphonates,Sufones and Esters with Electron‐Deficient Alkenes

1,3‐Dipolar cycloaddition of diazo compounds with olefinic substrates is a promising atom‐economic strategy for the construction of functionalized pyrazoles. Over the last few years, our group has been engaged in the synthesis of phosphonyl/sulfonylpyrazoles and pyrazole esters by employing Bestmann‐Ohira Reagent (BOR) and its sulfur and ester analogs as 1,3‐dipole precursors with various dipolarophiles. This account describes the novel synthetic methods developed in our laboratory, in the perspective of closely related work by others, for the synthesis of phosphonyl/sulfonylpyrazoles, pyrazole esters and the total synthesis of Withasomnine, a natural product, by using 1,3‐dipolar cycloaddition as the key step.     

Synthesis,Characterization and Magnetic Properties of New Dinuclear Copper(II) Complexes with N,N′‐Disubstituted Dithiooxamides derived from α‐Amino Acids

Four new dinuclear copper(II) complexes have been synthesized and have the general formula [Cu₂(L)(H₂O)₂], where L = GLYDTO [N,N′‐bis(carboxymethyl)dithiooxamide], ALADTO [N,N′‐bis(carboxyethyl)dithiooxamide], VALDTO [N,N′‐bis(1‐carboxy‐2‐methylpropyl)dithiooxamide] and LEUDTO [N,N′‐bis(1‐carboxy‐3‐methylbutyl)dithiooxamide]. The complexes were characterized by elemental analysis as well as by IR, electronic and EPR spectroscopy. These techniques provided evidence for the presence of the CuNO₂S chromophore. Magnetic susceptibility measurements on all the complexes in the range 4–300 K show the existence of a dominant antiferromagnetic interaction with ?J values greater than 300 cm^?1. Thermal decomposition behaviour of the complexes was studied by thermogravimetry.     

Asymmetric Diels–Alder and Inverse‐Electron‐Demand Hetero‐Diels–Alder Reactions of β,γ‐Unsaturated α‐Ketoesters with Cyclopentadiene Catalyzed by N,N′‐Dioxide Copper(II) Complex

Highly enantioselective Diels–Alder (DA) and inverse‐electron‐demand hetero‐Diels–Alder (HDA) reactions of β,γ‐unsaturated α‐ketoesters with cyclopentadiene catalyzed by chiral N,N′‐dioxide–Cu(OTf)₂ (Tf=triflate) complexes have been developed. Quantitative conversion of β,γ‐unsaturated α‐ketoesters and excellent diastereoselectivities (up to 99:1) and enantioselectivities (up to >99 % ee) were observed for a broad range of substrates. Both aromatic and aliphatic β,γ‐unsaturated α‐ketoesters were found to be suitable substrates for the reactions. Moreover, the chemoselectivity of the DA and HDA adducts were improved by regulating the reaction temperature. Good to high chemoselectivity (up to 94 %) of the DA adducts were obtained at room temperature, and moderate chemoselectivity (up to 65 %) of the HDA adducts were achieved at low temperature. The reaction also featured mild reaction conditions, a simple procedure, and remarkably low catalyst loading (0.1–1.5 mol %). A strong positive nonlinear effect was observed.