A Novel Synthesis of 1-Aminoalkanephosphonic Acid Derivatives from 1-(N-Acylamino)- alkyltriphenylphosphonium Salts

Efficient and convenient procedures for the α-amidoalkylation of trialkylphosphites with 1-(N-acylamino)alkyltriphenylphosphonium salts followed by a Michaelis–Arbuzov-type reaction to afford 1-(N-acylamino)alkanephosphonic acid esters have been developed. High yields and simple isolation and purification protocols are the main advantages of this method.     

多组份一锅法合成新型2-取代噻唑-4-甲酸衍生物

以甲醇为溶剂,以醛、胺、硫代乙酸和3-(二甲氨基)-2-异氰基丙烯酸甲酯为原料,经四组份一锅法反应合成了9个新型的2-取代噻唑-4-甲酸衍生物,产率25%~54%,纯度90.3%~100%,其结构经1H NMR,13C NMR和LC-MS表征。     

Reaction of 1-Acetyl-5-hydroxy-2-phenylpyrazolidines with Amino Acid Esters

Reaction of 1-acetyl-2-phenyl-5-hydroxypyrazolidines with amino acid esters occurs to give the corresponding N-pyrazolidinyl amino acids under mild conditions.     

Reaction of Long-Chain Vanillyl Esters with CH-Acids and 2-Naphthylamine

The previously unknown 4-(alkyl-11-oxo-7,8,9,10,11,12-hexahydrobenzo[a]acridin-12-yl)- and 4-(alkyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)-2-methoxyphenyl esters of aliphatic (C₅-C₇, C₁₂) carboxylic acids were synthesized via cascade heterocyclization of cyclohexane-1,3-dione and dimedone with 2-naphthylamine and long-chain vanillyl esters.     

Synthesis of Thiol Esters by the Reaction of Ricinoleic Acid with Thiols Under Solvent-Free Conditions

The synthesis of several ricinoleic acid thiol esters starting from cis-(R)-12-hydroxyoctadec-9-enoic acid and thiols in the presence of N,N′-dicyclohexylcarbodiimide (DCC) is described. The method is efficient for aromatic and aliphatic thiols, selectively affording the respective fat acid thiol esters in good yields under mild, neutral, and solvent-free conditions. The protocol is general and was extended to other carboxylic acids, furnishing the desired products in satisfactory yields. The (R,Z)-12-hydroxy-octadec-9-enylic acid benzylthiol ester 3a was successfully reduced to (R,Z)-12-hydroxyoctadec-9-enal 4.      

Four-Component Synthesis of Disubstituted 1,3,4-Oxadiazoles from N-Isocyaniminotriphenylphosphorane,Phenylacetylenecarboxylic Acid,Chloroacetone Derivatives,and Primary Amines

The 1:1 imine intermediate generated by the addition of primary amine to chloroacetone derivatives is trapped by N-isocyaniminotriphenylphosphorane in the presence of phenylacetylenecarboxylic acid, leading to the formation of the corresponding iminophosphorane intermediate. Disubstituted 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediate. The reactions were completed in neutral conditions at room temperature. The disubstituted 1,3,4-oxadiazole derivatives were prepared in excellent yields.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Interaction of Hydroxylamine with Esters of 2-Oxobutenoic Acids. Synthesis of 1-Hydroxy-3-hydroximino-2-pyrrolidinones

New 3-hydroximino-1-hydroxy-2-pyrrolidinones have been synthesized by the interaction of NH₂OH and NH₂OBn with the methyl esters of 2-oxo-3-butenoic acid derivatives. Some intermediate compounds have been isolated and identified and the reaction mechanism is discussed.     

Synthesis of Some Pyrimidine 2-Oxo(Thio)-4,6-Dione Derivatives

5-Arylidenes 1a and 1b, on reaction with ethyl cyanoacetate and diethyl malonate in the presence of ammonium acetate under Michael condensation, yield pyridine derivatives 2 and 3, respectively. Cyclopentapyrimidine derivative 4 can also be obtained by the reaction of 1a with malononitrile in the presence of piperidine. The reaction of 5-arylidene lb with monochloroacetic acid in an alkaline medium gives the thiazol derivative 5. Also, spiro-[3′, 5′]cyclohexenyl pyrimidine derivative 6 could be obtained from the reaction of 1d with maleic anhydride. On the other hand, 5-arylidene 1e reacts with maleic anhydride to give 2-thiobarbituric acid derivative 7. The condensation reaction of 2-thiovioluric acid 8 with some hydrazines affords the triazole derivatives 9a-d. Finally, barbituric acid condenses with isatin to give 5-arylidene 1f, which can be cyclized with phosphorous pentoxide to afford 10.     

Synthesis of Derivatives of 2-(Indol-1-yl)propionic Acids

We have developed a method for synthesis of N-substituted derivatives of indole from N-phenylalanine, including Fischer cyclization of the corresponding arylalkylhydrazones. The starting hydrazines were obtained by reduction of the corresponding nitrosamines. We have established that the optimum reduction method is to use metallic zinc in a methanol-hydrochloric acid system at low temperatures.     

Unnatural Amino Acids. 2. Simple Method of Obtaining Esters of Aziridine-2-carboxylic Acids by a Transesterification Reaction

A series of N-unsubstituted esters of aziridine-2-carboxylic acid has been obtained by transesterification in basic medium using primary, secondary, and tertiary alcohols. Methods of transesterification using various bases (K₂CO₃, ROLi, t-BuOK) have been compared. Transesterification with lithium alcoholates also affords the possibility of obtaining esters of N-substituted aziridine-2-carboxylic acids. Transesterification of chiral esters proceeds with retention of the configuration of the chiral center.     

Synthesis of oxo-Phosphoranylidene Aminobenzoic Acid Derivatives by a Multicomponent Reaction

2-Aminobenzoic acids or 4-aminobenzoic acid react with dimethyl acetylenedicarboxylate/triphenylphosphine in less than 20 min at 15–25°C to produce new organic phosphorus compounds in good to excellent yields. The conversion occurs with selective N- over O-alkylation of the amino group and isolation of the products is accomplished simply by filtration.     

Electrolysis of Nitro Compound Salts: Application in Ketone Synthesis

One-pot electrochemical method of synthesis of ketones, diketones, and esters of monoketo- and diketoalkanoic acids is elaborated. This method is based on the diaphragmless galvanostatic electrolysis of Na salts of secondary nitro compounds—derivatives of nitrohydrocarbons, nitroketones, and esters of nitrated alkanoic acids—in methanol.     

4-二甲基氨基吡啶催化合成N-保护氨基酸三氟乙酯

合成了6个未见文献报道的N-保护氨基酸三氟乙酯。4-二甲基氨基吡啶对N-保护氨基酸三氟乙酯的合成具有较高的催化活性,使三氟乙酯的合成产率大大增加。     

Synthesis of N-Alkylated Derivatives of Pyrazolo[1,5-a]pyrimidine and Their Reaction with Methylamine

With the object of studying the factors influencing the course of enamine rearrangements, we have carried out the N-alkylation of alkyl- and aryl-substituted pyrazolo[1,5-a]pyrimidines. Using the NOEDIF NMR spectroscopic method for the cases of 5,7-dimethyl-2-phenyl- and 2,5,7-triphenylpyrazolo[1,5-a]pyrimidines it was found that addition of the alkyl group occurs at the N₍₄₎ atom of the pyrimidine fragment in the pyrazolo[1,5-a]pyrimidine. It was shown that, when reacting with an alcoholic solution of methylamine, the 5,7-dimethyl-2-phenyl- and 2,5,7-triphenylpyrazolo[1,5-a]pyrimidine iodomethylates undergo decomposition to give 5-methylamino-3-phenylpyrazole and 5-(1,3-diphenyl-3-methylamino-2-propenylid-1-ene)amino-3-phenylpyrazole.     

Complexes of Lanthanide Nitrates with Alkyl Esters of Bromomethylenediphosphonic Acid

Complexes of lanthanide nitrates (La, Ce, Sm, Gd, Er, and Yb) with tetraethyl and tetraisopropyl esters of bromomethylenediphosphonic acid were prepared. The complexes were characterized by elemental analysis, IR spectroscopy, and, in some cases, NMR. The data confirm that diphosphonates coordinate with two P[dbnd]O groups, and there are no indications for the existence of noncoordinated P[dbnd]O groups. The structure of the complexes depends only on the ionic radius of the central metal atom and not on changes in the electronic or steric behavior of the ester groups. For the complexes of La, Ce, Sm, and Gd nitrates, the formula is LnL₂(NO₃)₃, and for Er and Yb nitrates it is Ln₂L₃(NO₃)₆ (Ln[dbnd]La, Ce, Sm, Gd, Er, Yb; L = diphosphonate).     

不对称Petasis反应在手性胺类化合物合成中的应用

手性胺类化合物广泛存在于天然产物、药物分子和多功能材料中,而且作为重要中间体、催化剂和手性辅剂在有机合成中也有广泛的应用,因此,发展高效的方法合成各种手性胺化合物及相应的骨架结构具有重要的科学意义和应用价值.有机硼试剂、胺和羰基化合物参与的不对称Petasis三组分反应是构建手性胺及其衍生物最简洁、高效的方法之一.近年来,利用该策略来构建手性胺类化合物引起了广泛的关注.文章综述了不对称Petasis反应合成手性胺类化合物的近期研究进展,主要包括手性胺源、手性羰基化合物和手性硼试剂参与的底物诱导的不对称Petasis反应,以及手性催化剂促进的不对称Petasis反应,并对该领域的挑战和未来发展方向进行简要讨论.     

The Reaction of (N-Isocyanimino)triphenylphosphorane with Anthranilic Acid Derivatives: One-Pot Synthesis of 2-Substituted 1,3,4-Oxadiazoles via Intramolecular Aza-Wittig Reaction

The reaction of anthranilic acid derivatives with (N-isocyanimino)triphenylphosphorane proceeds smoothly at room temperature to afford 2-substituted 1,3,4-oxadiazoles via an intramolecular aza-Wittig reaction in excellent yields under neutral conditions. The structures of the products were deduced from their IR, ¹H NMR, and ¹³C NMR spectra and mass spectrometry.