Phosphinic Acid Analogues of Thiaproline and the Related Heterocyclic Aminophosphinic Acids

Bis(trimethylsilyl) phosphonite adds in a 1,2 fashion to the C = N bond in 3-thiazolines 3a-d to give after hydrolysis phosphinic acids 5a-d. Starting from 3-oxazines, the corresponding 6a,b phosphinic acids 7a,b were obtained.     

Non-hydrolysable Phosphinic Analogues of Dipeptides

Abstract

Peptide analogues 1 in which the phosphonamide group replaces the amide function are thought to mimic the tetrahedral intermediates and transition states in peptide hydrolysis. While pepti-des 1 are potent inhibitors of some peptidases, their unsefulness is limited by rapid hydrolysis of P-N bond in aqueous media. To circumvent the instability problem we designed peptide analogues 2 with a CH₂ group inserted between the phosphorus and nitrogen atoms. Such structures are resistant to hydrolysis but it was interesting to see if they are similar enough to pepti-des to retain any affinity to enzyme active sites.     

α-硫羰基膦酸衍生化喹唑啉酮含磷类似物的研究

研究了两种不同的合成路线，合成１７个新的α－硫羰基膦酸衍生化喹唑啉酮含磷类似物２ａ－２ｑ，其结构经ＮＭＲ，ＩＲ，ＭＳ和元素分析表征，通过单晶Ｘ射线衍射分析，探讨了稠杂环标化合物的立体化学特征，并对其１，３位取代棋的氢谱磁不等价现象进行了合理解释。     

Pyrolysis of Amino Acid Derived Stabilised Ylides as a Route to Chiral Acetylenic Amines and Amino Acids and Gaba Analogues

Abstract

We recently reported the pyrolysis of stabilised ylides as a method for overall conversion of carboxylic acids to homologous acetylenic esters and terminal alkynes.^1,2 This has now been applied successfully to amino acids. A wide range of alkoxycarbonyl protected amino acids have been converted to the stable crystalline ylides 1. These have been fully characterised, and upon FVP, eliminate Ph₃PO to afford the protected acetylenic amino acids 2 in good yield and without significant racemisation. Subsequent reactions of these extremely versatile intermediates have been used to gain access to a wide variety of chiral amine and amino acids of great interest as potential selective enzyme inhibitors and components for modified peptide structures.     

New Sol-Gel Routes to Organic-Inorganic Hybrid Materials: Modification of Metal Alkoxide by Phosphonic or Phosphinic Acids

Hybrid materials were synthesized by modification of Ti(O ⁱ Pr)₄ by diphenyl phosphinic (DPPA) or phenyl phosphonic acid (PPA). Different P/Ti and H₂O/Ti ratios have been investigated. The samples were characterized using FTIR and ³¹P MAS NMR spectroscopies, elemental analysis (EDX), and N₂ adsorption-desorption experiments. Both PPA and DPPA act as chemical modifiers. Depending on the H₂O/Ti and P/Ti ratios, and on the nature of the modifier (PPA or DPPA), molecular Ti oxo-alkoxo-phosphonates or phosphinates, stable sols, gels, or precipitates were obtained. In addition, the P/Ti ratio was retained during the hydrolysis whatever the H₂O/Ti ratio.     

含1,2,3-苯并三氮唑及嘧啶衍生物醚类化合物的合成及除草活性

嘧啶氧醚类化合物是一类新型除草剂,对其进行结构修饰以寻求具有更高活性的先导化合物是当前乙酰乳酸合成酶(ALS)类除草剂研究中的一大热点.近年来对嘧啶氧醚类化合物修饰主要集中在苯环部分取代基的变化上,而杂环部分为稠杂环的醚类化合物报道很少[1～3].在对嘧啶醚类除草剂构效关系研究中发现其与ALS相互作用时,杂环部分主要起供电子作用,其供电子能力越强化合物的活性越高[4].另外,许多二芳醚类化合物又是原卟啉原氧化酶(PPO)抑制剂,我们初步研究发现,1,2,3-苯并三氮唑是一类很好的活性单元,若在醚类化合物中引入这种稠杂环有可能找到高活性的先导化合物.     

Heterocyclization of Aromatic Amino Acids: Novel Syntheses and Antibacterial Activity of Fused,Non-fused,and Spiro Polyheterocyclic Derivatives

Russian Journal of Organic Chemistry - Commercially available p-aminobenzoic acid was used as a precursor for the synthesis of novel fused, non-fused, and spiro polyheterocyclic derivatives bearing...     

Synthesis of Aromatic Amino Acid Amides

Aromatic amino esters, in toluene or water, react with aqueous ammonium hydroxide to give moderate to high yields of the corresponding amides.     

The Biosynthesis of Aromatic Amino Acids and its Regulation

Microorganisms synthesize the aromatic amino acids phenylalanine, tyrosine, and tryptophan, as well as the related compounds p-aminobenzoic acid, tetrahydrofolic acid, p-hydroxybenzoic acid, ubiquinone, vitamin K, and nicotinic acid, by a highly branched route passing through shikimic acid. The biosynthesis is not regulated in the same way in all the organisms studied. The regulation is strongly dependent on the ability of the enzymes involved to be resolved into isozymes, their ability to be inhibited, and their activation, repression, and induction.     

氨基膦酸树脂对镱的吸附及机理

氨基膦酸树脂 ( APAR)对镱 ( )的吸附在 p H=5 .1时最佳。静态饱和吸附容量为 2 75 mg/g千树脂 ;用 3.0～ 4.0 mol· L- 1HCl能还原洗脱。测得吸附速率常数k2 98=9.5 7× 1 0 - 6 s- 1,等温吸附服从 Freundlich经验式 ,吸附热力学函数△ H0 =1 7.6k J· mol- 1。吸附机理表明 ,APAR功能基上的 N、O与 Yb3+发生配位键合 ,配位摩尔比为 2∶ 1     

The Design and Synthesis of Bone-Active Phosphinic Acid Analogues: 1. The Pyridylaminomethane Phosphonoalkylphosphinates

Abstract

The bisphosphonic acids and their salts, the bisphosphonates, have been the subject of study by a number of research groups for their marked ability to modulate bone metabolism. From a recent study of phosphinic acid isosteres, we have designed a novel related class of bone active agents, the pyridylaminomethane phosphonoaikylphosphinates I.     

Preparation of Novel Piperidine Phosphinic Acid Analogues of the Inhibitory Neurotransmitter γ-Aminobutyric Acid (GABA)

Abstract

Novel pipendine phosphinic, methylphosphinic and phosphonic acids were synthesized (5a-5c and 6 in the figure). The acids are bioisosteres of the corresponding carboxylic acid isonipecotic, which is a GABAA agonist.     

Synthesis,Crystal Structure and Complexing Properties of Phosphinic Analogues of Glycylglycine

Abstract

The phosphinic dipeptides of the general formula H₂NCH₂CONHCH₂P(R)(O)(OH) where R?Me, Ph and t-Bu has been synthetized from the free phosphinic acids and N-hydroxnunimide esters of the N-protected glycine. The deprotected dipeptida were purified by combination of the column chromato graphy on strong and week cation exchange resins by elution with diluted aqueous ammonia (0.1–3%)     

Determination of Complexation Selectivity of Aromatic Phosphonic Acids by Ammonium and Potassium Cations Using CE

Benzyl phosphonic acid, meta and para xylene diphosphonic acid and mesytilene triphosphonic acid were previously synthesized. Now we wanted to evaluate the ability of these compounds to complex selectively potassium and ammonium cations. We based our work on two different strategies. First we used Capillary Electrophoresis for calculating the binding constants. They enabled us to calculate the preferential binding energy, in other words the thermodynamic selectivity of complexation. Secondly, we used molecular mechanics to evaluate the difference of stability of the complexes. The results obtained in Capillary Electrophoresis appeared consistent with those obtained in molecular mechanics and, consequently, we demonstrated that mesytilene triphosphonic acid leads to the best selectivity of complexation towards ammonium and potassium cations. This complexation selectivity was shown, as an example, through the separation of four monovalent cations obtained in capillary zone electrophoresis. The evolution of complexing properties was discussed by referring to the structure of the studied phosphonic acids.