Sm/AlCl3·6H2O体系促进的叠氮化合物的化学选择性还原:一种制备胺的新方法

在金属钐和六水合三氯化铝的存在下 ,叠氮化合物能在温和及中性条件下高产率地被还原为相应的胺     

Reduction of Azides to Amines with New Metal／Lewis Acid Systems in H2O or Aqueous EtOH

The azides were reduced to the corresponding amines by two new meml/LEwis acid systems in water or in aqueous EtOH in yields ranging from 80%-95%. The reaction rates were faster in water than in aqueous EtOH in most cases. All 16 azides with different functional groups were well reduced to the corresponding amines in excellent yields and reaction rates.     

NaBH4/BiCl3复合体系还原芳香硝基化合物为氧化偶氮苯及其类似物

NaBH4/BiCl3复合体系在甲醇介质中对硝基化合物进行部分还原,可以获得相应的氧化偶氮苯类化合物。实验中发现此反应与反应底物的Hammett常数有着密切的关系。     

二级胺与羰基化合物的一步还原烷基化

碲试剂作为还原剂已得到较广泛的应用,Yamashita、周洵钧将NaHTe用于羰基化合物还原胺化为二级胺,Kambe等近期用H_2Te还原烯胺、亚胺到相应的胺,我们曾用NaHTe将二级胺与羰基化合物还原烷基化。本文采用不同二级胺进一步研究发现,脂肪环胺与醛的反应效果较好,同一条件下烯胺也可被还原,反应条件温和,脯氨酸酯还原烷基化的产物不发生明显消旋化(表1,3),可应用于氨基酸类反应。     

芳香硝基化合物还原制备芳胺的研究进展

综述了芳香硝基化合物还原制备芳胺的方法及近年的研究进展.其方法主要包括催化氢化法、CO/H2O还原法、金属还原法、硫化碱还原法、金属氢化物还原法、电化学还原法和光化学还原法.其中催化氢化法中的氢气还原法和水合肼还原法符合绿色化学的理念,并且反应收率高,选择性好,具有很高的应用价值.     

Ferrous Sulfide/Aqueous Ammonia: Simple,Efficient, and Chemoselective Reagent for the Conversion of Aromatic Azide to Amine

A practical, environmentally benign, rapid, and efficient method for the reduction of aromatic azide to amine is described using FeS/aqueous ammonia in the presence of other reducible functionalities. Application of a novel reducing reagent results in aromatic amines with excellent yield and high chemoselectivity, without need of any purification techniques.     

The Photocatalyzed Reduction of Aqueous Sodium Carbonate Using Nano SrFeO3

Heterogenous photocatalyzed reduction of aqueous Na2CO3 has been carried out by using nano SrFeO3 semiconductor powders.Formic acid,formaldehyde and methyl alcohol were identified as photoproducts,and were measured spectrophotometrically.The effect of the variation of different parameters such as sodium carbonate concentration,amount of photocatalyst and different light sources on the yield of photoproducts was also investigated.It shows that nano SrFeO3 has photocatalytic activity.Irradiation leads to the production of electrons in the conduction band of the SrFeO3 semiconductor.It is likely that the photoproduced electrons reduce CO3^2- initially to HCOO^-,and then to HCHO and CH3OH.     

Spectrophotometric Determination of Iron(III) as Azide Complexes in Aqueous Tetrahydrofuran

Abstract

A simple, sensitive and alternative method for the spectrophotometric determination of iron(III) has been established. The procedure is based on the formation of iron-azide complexes in 60% (v/v) tetrahydrofuran/ water medium. The high sensitivity obtained in this method is due to the use of an interesting absorption band not previously reported in the literature. In the recommended conditions, absorbances for the ferric complexes are measured at 400 nm where the molar absorptivity is 1.52 × 10⁴ 1 mol^?1 cm^?1. The organic solvent used increases the sensitivity and the stability of the measurements. The precision is shown by the average deviation of about 0.3%. This system obeys Beer's law and is suitable for iron(III) determination in the concentration range from 0.6 to 3.2 mg 1^?1 (ppm). The best experimental conditions were determined studying the different factors involved. The influence of various diverse ions was also studied.     

二苯酮-可聚合胺引发1,6-己二醇二丙烯酸酯的光聚合研究

以UV-Vis分光光度计法和Photo-DSC法分别研究了合成的3种可聚合胺类助引发剂DMPDA、EGDPM、EGMPM与二苯甲酮(BP)组成的引发体系的光化学初级过程及引发1,6-己二醇二丙烯酸酯(HDDA)的紫外光聚合动力学.考察了助引发剂胺的含量对BP的光化学初级过程和对引发HDDA光聚合动力学的影响,以及光强和温度对聚合动力学的影响.结果表明,随着胺含量的增加,BP的光化学初级反应速率增加,从而使体系的聚合反应速率增加.随着温度和光强的增加,单体最终转化率、最大反应速率增大,达到最大反应速率所需的时间减小.     

A Novel Synthesis of Benzyl Sulfides and Selenides via Sm/BiCl3 System in Aqueous Media

Benzyl sulfides and selenides are synthesized via reaction of benzyl bromide with disulfides and diselenides promted by Sm/BiCl₃ system in aqueous media in moderate to good yields.     

含氢硅油-三氯化钌催化酰胺的还原反应研究

以原位形成的膦钌络合物为催化剂,研究了含氢硅油对酰胺的还原反应,考察了酰胺的结构、反应溶剂、配体等条件对催化反应的催化效率及产物结构的影响.仲胺基及伯胺的酰胺化合物被还原成相应的叔胺及仲胺;丙烯酰胺与含氢硅油反应时,选择性较差,得到丙烯腈、丙腈及与硅烷基相连的聚丙烯酰胺与聚丙烯腈.     

Chemoselective Reduction of Tertiary Amides to Amines Catalyzed by Triphenylborane

Triphenylborane (BPh₃) was found to catalyze the reduction of tertiary amides with hydrosilanes to give amines under mild condition with high chemoselectivity in the presence of ketones, esters, and imines. N,N‐Dimethylacrylamide was reduced to provide the α‐silyl amide. Preliminary studies indicate that the hydrosilylation catalyzed by BPh₃ may be mechanistically different from that catalyzed by the more electrophilic B(C₆F₅)₃.     

Efficient Oxidation of Sulfide and Tertiary Amine by Molecular Oxygen/Aldehyde/Fe_2O_3 System

在温和的反应条件和催化剂Ｆｅ２Ｏ３存在下，结合使用分子氧和异戊醛，可高产率地发生硫醚氧化成亚砜和砜、叔胺氧化成氧化叔胺的反应。     

Sm/HOAc/EtOH System–Mediated Reduction of Baylis–Hillman Acetates

Selective formation of (2E)‐2‐methylalk‐2‐enoates or 2‐methyl alkanoates could be achieved in moderate to good yields under mild conditions via Sm/HOAc/EtOH system–mediated reduction of Baylis–Hillman acetates depending on the amount of samarium consumed in the reactions.     

Photocatalytic Conversion of Benzyl Alcohols/Methyl Arenes to Aryl Nitriles via H-Abstraction by Azide Radical

This report presents the visible-light-assisted synthesis of aryl nitriles from easily accessible alcohols or methyl arenes in the presence of O₂. Organic photoredox catalyst, 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene), induces single electron transfer (SET) from azide N₃⁻ and generates azide radical N₃⋅.The photogenerated N₃⋅ abstracts H atom from α-C−H bond of benzylic system, which provides aldehyde and hydrazoic acid (HN₃) in situ. This reaction subsequently forms azido alcohol intermediate that transforms into nitrile with the assistance of triflic acid (Brønsted acid). A range of alcohols and methyl arenes successfully underwent cyanation at room temperature with good to excellent yields and showed good functional group tolerance.     

Microcalorimetric Study on the Oscillating System of Two-phase Reaction of Aqueous Acid with Primary Amine in Chloroform

It has been found that the two-phase reactions of aqueous HCl,HOAc or H3PO4 with primary amine N1923 in chloroform are osiclating reactions.Their power-time curves were measured by the titration microcalorimetric method,and the induction period(tin).The first oscillating period(tp.1) and the second oscillating period (tp.2) were determined.The apparent activating parameters and the orders of the oscillating systems were calculated and the following relationships were established:for the oscillating system of hydrochloric acid.     

Synthesis of β-aminoesters and α-selenoesters via Active Metal Bismuth Produced by Sm/BiCl_3 System in Aqueous Media

Since the general approach for the preparation of highly reactive metal powders wasreported in 1972', active metals have attracted considerable attention in organicsynthesis'. Due to the high reactivity of active metals, reactions are typically carriedout more efficiently, under milder conditions, and with a wider array of substrates thanwith other current methods. UP to noW, active metal magnesium', zinc', indium',calcium', manganese', samarium', elc have been reported..Meanwhile, metal-medi…     

Mild and Efficient Deoxygenation of Amine-N-oxides with BiCl3/Indium System

The BiCl₃/indium system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under mild conditions.     

胺(或氨) - CHCl3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△εL-H及广义H键距离良好的线性关系,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。     

N,N-二甲基正十二烷基胺/无机含氧酸体系的相态结构研究

利用拟三元相图法研究了N,N-二甲基正十二烷基胺(DMDA)多元体系的相态结构,并用电导、偏光显微镜以及红外、紫外可见光谱等手段进行了表征.发现N,N-二甲基正十二烷基胺体系随水相含量的增加,铵盐发生不同形式的有序缔合,分别形成了W/O型微乳液、“节-结”型链状缔合体、层状液晶和O/W型微乳液;在层状液晶中,SO₄^2-主要以桥式双齿配位形式存在,中性胺分子有利于体系中液晶的形成;层状液晶于500nm波长处有一吸收峰,在430nm附近发生“光短路”现象,该现象可能对测定层状液晶的层间距有重要意义.