The Reaction of N-Isocyaniminotriphenylphosphorane with Cyclopentanone and A Primary Amine in the Presence of An E-Cinnamic Acid Derivative

Abstract

Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone in the presence of an E-cinnamic acid derivative and a primary amine proceeds smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.     

A Simple Simultaneous Colorimetric Determination of Primary and Secondary Amines with Fluorescamine

Abstract

Primary and secondary amines react reproducibly with fluorescamine to form pyrrolinones or aminoenone type chromophores with long wavelength absorption maxima in the 375–410 and 310–320 nm regions, respectively. A simple procedure has been worked out for the simultaneous colorimetric determination of primary and secondary amines.     

(R)-N-酰基四氢噻唑-2-硫酮-4-羧酸在DCC存在下与胺的反应

由Ｎ－乙酰四氢噻唑－２－硫酮－４－羧酸（［α］２０Ｄ－１０９．８３°），及Ｎ－苯甲酰四氢噻唑－２－硫酮－４－羧酸（［α］２０Ｄ－１１２．２２°），在Ｎ，Ｎ′－二环己基二亚胺（ＤＣＣ）存在下分别与环己胺、苯胺反应得到光学活性产物（Ｒ）－Ｎ－乙酰四氢噻唑－２－硫酮－４－甲酰环己胺（［α］１７Ｄ－７４．５°），及（Ｒ）－Ｎ－苯甲酰四氢噻唑－２－硫酮－４－甲酰苯胺（［α］１９Ｄ－７．０４°）。用量子化学ＰＭ３方法研究了反应物和产物的电子结构。     

A Simple Primary Amide for the Selective Recovery of Gold from Secondary Resources

Waste electrical and electronic equipment (WEEE) such as mobile phones contains a plethora of metals of which gold is by far the most valuable. Herein a simple primary amide is described that achieves the selective separation of gold from a mixture of metals typically found in mobile phones by extraction into toluene from an aqueous HCl solution; unlike current processes, reverse phase transfer is achieved simply using water. Phase transfer occurs by dynamic assembly of protonated and neutral amides with [AuCl₄]^? ions through hydrogen bonding in the organic phase, as shown by EXAFS, mass spectrometry measurements, and computational calculations, and supported by distribution coefficient analysis. The fundamental chemical understanding gained herein should be integral to the development of metal‐recovery processes, in particular through the use of dynamic assembly processes to build complexity from simplicity.     

Regioselective Monophosphorylation of Primary OH Groups in the Presence of Secondary OH Groups

With various model hydroxy compounds as examples, efficient procedures were developed for regioselective monophosphorylation of primary hydroxy groups in the presence of unprotected secondary hydroxy groups.     

不同稀释剂中N_(1923)的界面性质

研究了伯胺 N192 3在不同稀释剂 /0 .1 mol/L(H,Na) NO3(p H=2 .3 4)体系中的界面性质 ,计算了界面吸附特性参数 cmin和 AI.N192 3在不同稀释剂体系中的界面活性顺序为 :正庚烷 >环己烷 >苯 >甲苯 >四氯化碳 >氯仿 >醋酸异戊酯 >甲基异丁基酮 (MIBK) .这一结果可能与稀释剂和萃取剂、稀释剂和有机相中增溶水及萃取剂和界面层水分子之间的相互作用有关 .对有关结果及其与萃取性能的关系做了分析和讨论     

Electrochemical Oxidation of Dopamine in the Presence of Secondary Amine. An Alternative Way for Quantitative Dopamine Determination at a Gold Electrode

Electrooxidation of dopamine in the absence and presence of morpholine as a nucleophile was investigated on a gold electrode in phosphate buffer, pH 7. The results have shown that electrochemically produced dopaminoquinone undergoes an attack by morpholine via 1,4‐Michael addition. The reaction products have been identified by electrospray ionization mass spectrometry (ESI‐MS). The procedure used is suitable for quantitative dopamine determination in the presence of the ascorbic acid excess at a unmodified gold electrode.     

仲胺的合成方法新进展

介绍了近10年来合成仲胺的新方法,包括直接N-烷基化法,还原胺化法,苯并异噁唑类和2-羟基苯甲醛肟类的还原,三相反应法,保护-烷基化-去保护和不对称硼酸酯法。参考文献33篇。     

The Influence of Ketones on the Formation of Symmetrical Secondary Amine: A New Method for Preparation of N, N-Bis-(dimethoxyphenylethyl)amine

InthecourseofhydrogenationofiminetoprepareDDPH,whichisanadrenoreceptorant.agonistandundergoesclinicstudyinChinanow',oneforeignmaterialN,N-Bis(dimethoxyphenylethyl)amineIwasformed(Schemel)'.IisanimportantintermediateforthepreparationofarrhythmicagentYS0353'4.Herewewouldliketoexplainitsformationandtheinfluenceofketoneonitsyield.Inschemel,whenweusedRaneyNiW,ascatalystunder40atm.H,pressure,40*nd5%Iwereobtained.Forimprovingtheyieldof2,weareattemptingtoreplaceRaneyNiW,bybasicRaneynickelto…     

胺(或氨)一CHCI3系CT复合物密度泛函法研究

报道对氨(NH3,母体)、甲胺(CH3NH2)、二甲胺[(CH3)2NH]、三甲胺[(CH3)3N]与三氯甲烷(CHCL3)形成的系列复合物的理论研究结果．把复合物看作一个超分子,在B3LYP/6-311G(d,p)的水平上进行密度泛函法计算,并运用完全均衡校正法进行基组超位误差校正(BSSE).探讨该系列复合物的电子结构与相关性质,如稳定性、电荷转移及主要几何参数的变化规律等.结果表明,形成复合物的稳定性次序为NH3-CHCl3(Ⅰ)>CH3NH2-CHCL3(Ⅱ)>(CH3)2NH-CHCl3(Ⅲ)>(CH3)3N-CHCl3(Ⅳ).形成复合物的过程包含着电荷转移.该系列复合物的稳定性与电荷转移量、前线轨道能量差ΔεL-H及广义H键距离有良好的线性关系,与结合点的电荷布居也有密切的关系.复合物的稳定性是分子间共价作用和静电作用两方面因素综合的结果.计算结果能较好地解释有关的实验现象和规律.     

An Efficient and Simple Method for Diazotization-Thiocyanation of Aryl Amine using Cross-Linked Poly (4-Vinylpyridine) Supported Thiocyanate Ion

Abstract

An efficient and simple method for the facile synthesis of arylthiocyanates via diazotization-thiocyanation of aryl amines using cross-linked poly (4-vinylpyridine) supported thiocyanate ion is described. Various primary aromatic amines, with electron-withdrawing and electron-donating groups, were transformed into aryl thiocyanates in high to excellent yields in a short reaction time. The present procedure offers advantages such as short reaction time, simple reaction work-up, and the polymeric reagents can also be regenerated and reused for several times without significant loss of their activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

N-Cyanation of Primary and Secondary Amines with Cyanobenzio-doxolone (CBX) Reagent

An efficient electrophilic N-cyanation of amines with a stable and less-toxic cyanobenziodoxole reagent towards the synthesis of cyanamides is disclosed. This synthetically practicable strategy allows the construction of a wide variety of cyanamides under very mild and simple conditions with a broad functional group compatibility, and showcases a huge potential in late-stage modification of complex molecules.     

Selective Oxidation of Secondary Alcohols in the Presence of Primary Alcohols by an Oxoammonium Salt

Recent reports on the oxidation of alcohols by piperidine oxoammonium salts(1) have aroused much interest in investigation.Semmelhack has found that alcohols can be electrooxidized to aldehydes or ketones at a low potential when the reaction is mediated with 2,2,6,6-tetramethylpiperidinyl-l-oxy radical (2a) and proposed that the oxoammonium ion (la) is the active oxidizing     

A Simple Method for Evaluating the Bioactive Phenolic Compounds’ Presence in Brazilian Craft Beers

There are a significant number of analytical methodologies employing different techniques to determine phenolic compounds in beverages. However, these methods employ long sample preparation processes and great time consumption. The aim of this paper was the development of a simple method for evaluating the phenolic compounds’ presence in Brazilian craft beers without a previous extraction step. Catechin, caffeic acid, epicatechin, p-coumaric acid, hydrated rutin, trans-ferulic acid, quercetin, kaempferol, and formononetin were analyzed in fifteen different craft beers. The method showed good linearity (R² ≥ 0.9966). The limit of detection ranged from 0.08 to 0.83 mg L⁻¹, and limits of quantification were between 0.27 and 2.78 mg L⁻¹. The method showed a satisfactory precision (RSD ≤ 16.2%). A good accuracy was obtained by the proposed method for all phenolic compounds in craft beer (68.6% ˂ accuracy ˂ 112%). Catechin showed higher concentrations (up to 124.8 mg L⁻¹) in the samples, followed by epicatechin (up to 51.1 mg L⁻¹) and caffeic acid (up to 8.13 mg L⁻¹). Rutin and formononetin were observed in all analyzed samples (0.52 mg L⁻¹ to 2.40 mg L⁻¹), and kaempferol was less present in the samples. The presence of plant origin products was determinant for the occurrence of the highest concentrations of phenolic compounds in Brazilian craft beers.     

萃淋树脂伯胺N1923对钯（Ⅱ）的萃取吸附机理（Ⅱ）

研究了伯胺Ｎ_（１９２３）萃淋树脂在Ｎ_（１９２３）成盐及不成盐时吸附钯的反应机理，通过等摩尔系列法、斜率法、红外光谱及核磁共振谱法对吸萃物的组成及吸萃机理进行了探讨。     

四氟乙烯五聚体与胺基化合物的反应

四氟乙烯五聚体(1),在 DMF 存在下与氨基磺酸反应,可生成2a,2b 与2c,并在2a 与2b 的分子中引入了 N,N-二甲胺基酮亚胺基。1与γ-氨基丙基三乙氧基硅烷(KH-550)反应,可得到烯亚胺及其环化产物环丁烯亚胺。根据~(19)F 和~(29)Si NMR 确证生成了 SiF_n(OEt)_(3-n)结构产物,n 可受反应条件控制,能起到瞬时交联的作用。1与乙醇胺的反应产物和四氟乙烯四聚体与乙醇胺反应结果类似, 得到七员环化物,但产率很高,可能是五聚体结构的反应活性较四聚体为大。四个脂肪族伯胺的反应活性顺序是正丁基胺,KH-550>乙醇胺>氨基磺酸。     

A Refined Method for the Removal of the Methoxymethyl (MOM) Protecting Group for Carbinols with Acidic Ion-Exchange Resin

The methoxymethyl protecting group for carbinols is best removed from acid-sensitive substrates by hydrolysis in aqueous methanol using a cationic exchange resin (Dowex-50W).