Copper-mediated synthesis of N,N′-diarylhydrazines from boronic acids

N,N＇-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.     

N－甲基吡咯烷酮、α－吡咯烷酮合成物系气相色谱分析

 This paper describes a GC analytical method in the synthes is of N-methyl pyrrolidone of a-pyrrolidone.This procedure was performed with a column packed with 6%OV-17/silanized 101 support and FID detec-tor. Calibration factors and detection conditions are given,The coefficients of variation of NMP and a-P were0.6%and 0.5%respectively. The relative errors of all the components were not more than±3.0%,Thequantitative analysis is fast,simple and accurate.     

EFFECT OF N,N,N’,N’-TETRAALKYL TEREPHTHALAMIDE ON NON-ISOTHERMAL CRYSTALLIZATION KINETICS OF POLYPROPYLENE

The effect of N,N,N＇,N＇-tetraalkyl terephthalamide （TATA） on the non-isothermal crystallization and melting characteristics ofpolypropylene （PP） was studied. The addition of TATA can lead to the formation ofβ-crystal PP. With the increase in TATA concentration the degree of crystallinity for β-crystal PP increased significantly, and that for a-crystal PP decreased, which indicated that TATA effectively induced the formation of β-crystal PP. WAXD also revealed the existence of β-crystal PP after the introduction of TATA into PP. PP containing TATA crystallized at a temperature range of 5-10℃ higher than that of pure PP, and the half-crystallization time （t1/2） and Avrami exponent （n） of PP at the same cooling rate were decreased by the addition of TATA, indicating that TATA influenced the crystallization rate and crystallization growth mode of PP. The rate constant of crystallization of PP containing TATA （Zc） was larger than that of pure PP, which further indicated that the crystallization of PP was accelerated by the addition of TATA.     

Studies on Synthesis and Biological Activities of Novel Triazole Compounds Containing Pyrimidine or N, N－Dialkyldithiocarbamate Ring

Twelve of the title compounds were synthesized. Their structures were identified by means of IR, EA, IH NMR and MS. The IR spectra clearly show that the absorptions in the regions of 1716—1666 cm^-1 and 1505—1499 cm^-1 are the characteristic absorption bands for vc=O and vc=N. In the IH NMR spectra of target compounds(10a—10g), three protons of a = CH—CH2— group present three sets of quartet peaks of the protons. The preliminary bioassays showed that the synthesized compounds exhibited some activities of fungicides and plant growth regulators.     

N，N，N′，N′-四丁基丙二酰胺从硝酸盐介质中萃取铈(Ⅲ)

Study on the extraction and separation of rare earth with new extractants is important in the rare earth chemistry and nuclear reprocessing. In this work， the extraction of Ce(Ⅲ) with N，N，N′，N′-tetrabutylmalonamide (TBMA) in toluene from nitrate media has been investigated. The effect of the concentration of nitric acid， TBMA and salt-ing-out agent (LiNO₃) and also the temperature on the distribution ratios was examined. The stoichiometries of the extracted complexes were determined to be Ce(NO₃)₃·3TBMA and Ce(NO₃)₃·4TBMA， respectively. The ap-parent extraction constants and the enthalpy of the extraction were calculated based on the extraction data， which are logK_ex1=3.97， logK_ex2=4.75 and Δ_rH_m^?=-31.25kJ·mol^-1， respectively. The IR spectra of the loaded organic phase supported the suggested extraction mechanism.     

N－（N＇，N＇－二甲氨基甲基）丙烯酰胺－过硫酸钾引发丙烯酰胺聚合的研究

Ｎ－（Ｎ＇，Ｎ＇－二甲氨基甲基）丙烯酰胺－过硫酸钾引发丙烯酰胺聚合的研究潘松汉，唐康泰，王贞，王真智中国科学院广州化学研究所，广州，５１０６５０关键词Ｎ－（Ｎ＇，Ｎ＇－二甲氨基甲基）丙烯酰胺、反应动力学、氧化还原体系、相对分子质量及分布为了制备高质量...     

Fluorescence Quenching of Anthracene by N,N－Diethylaniline and Phenothiazine in Triton X－ 100／n－C10H21OH／H2O Microemulsion

The photo-induced electron transfer reactions of anthracene with N, N-diethylaniline (DEA) and phe-not hiazine(PTZ) occur in the membrane phase of a Triton X-100/n-C10H21OH (1-decanol)/H2O microemul-sion. DEA and PTZ exist in the membrane phase of the microemulsion. Anthracene exists in the oil continu-ous phase of the W/O microemulsion and in the oil core and membrane phase of the O/W microemulsion.     

Evaluation of Transient Absorption Spectra of N,N,N’,N’—Tetra—（p—methylphenyl）

Photoinduced electron transfer processes between fullerenes(C60/C70)and N,N,N’,N’-tetra-(p-methylphenyl-4,4’-diamino-1,1’-diphenyl ether(TPDAE)have been studied by nanosecond laser flash photolysis.Quantum yields and rate constants of electron trasfer from TPDAE to excited triplet state of fullerenes(C60/C70)in benzonitrile have been evaluated by observing the trasient absorption bands in the near-IR region where the excited triplet state.radical anion of fullerenes(C60/C70)and radical cations of TPDAE appear.     

EFFECT OF N,N,N~'''',N~''''-TETRAALKYL TEREPHTHALAMIDE ON NON-ISOTHERMAL CRYSTALLIZATION KINETICS OF POLYPROPYLENE

The effect of N,N,N',N'-tetraalkyl terephthalamide (TATA) on the non-isothermal crystallization and melting characteristics of polypropylene (PP) was studied. The addition of TATA can lead to the formation of β-crystal PP. With the increase in TATA concentration the degree of crystallinity for β-crystal PP increased significantly, and that for α-crystal PP decreased, which indicated that TATA effectively induced the formation of β-crystal PP. WAXD also revealed the existence of β-crystal PP after the introduction of TATA into PP. PP containing TATA crystallized at a temperature range of 5-10℃ higher than that of pure PP, and the half-crystallization time (t1/2) and Avrami exponent (n) of PP at the same cooling rate were decreased by the addition of TATA, indicating that TATA influenced the crystallization rate and crystallization growth mode of PP. The rate constant of crystallization of PP containing TATA (Zc) was larger than that of pure PP, which further indicated that the crystallization of PP was accelerated by the addition of TATA.     

Helix—Sense—Selective Polymerization of N,N—Diphenyl （Meth） acrylamide by Anionic Catalysts

In this paper, the helix-sense-selective polymerization of N,N-diphenyl acrylamide (DPAA) and N,N-diphenyl methacrylamide (DPMAA) were studied with living helix prepolymer as anionic initiator, and the chiral optical properties of the obtained polymers were investigated too. It was shown that optically active polymers of DPAA and DPMAA could be obtained under the experimental condition, and exhibited the same screw sense as that of the prepolymer.     

Towards click chemistry: Multicomponent reactions via combinations of name reactions

In this report, we try to show the importance of incorporation of name reactions in the sequential cascade reaction in which significantly decreasing the number of steps towards an ideal and practical multi-step synthesis of natural products as well showing virtually all the advantages already mentioned for “Click Chemistry”. In addition, since the chiral inductions are desired for most of these sequential name reactions, their asymmetric catalyzed reactions were also described.     

Recent advances in ionic liquids: green unconventional solvents of this century: part II

Abstract

In the second part of our paper, further recent developments of ionic liquids in selected name reactions of carbonyl chemistry such as Mannich, Reformatsky, Cannizaro, Streacker, Barbier, Pechmann, etc. are described.     

Competitive thermal ene reaction and Diels-Alder reactions of 2-[N-(alk-2-enyl)benzylamino]-3-vinylpyrido[1,2-a]pyrimidin-4(4H)-ones

Thermal reaction of 2-[N-(alk-2-enyl)benzylamino]-3-(2-substituted and 2,2-disubstituted)vinylpyrido[1,2-a]pyrimidin-4(4H)-ones gave azepine, the desired ene products, and/or pyran derivatives. The formation of the latter was responsible for the [4+2] cycloaddition reaction between the α,β-unsaturated ester carbonyl moiety as a diene part and the alkenylamino moiety as an ene one. The reaction features depended upon the kinds of substituents both on the vinyl and alkenyl counterparts; strongly electron-withdrawing substituents on the vinyl moiety or an electron-donating substituent on the alkenyl one changed the reaction feature from the ene reaction to the hetero Diels-Alder reaction.     

Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate) catalyzed Suzuki, Heck, Sonogashira, and cyanation reactions

Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate): a structurally well-defined O-containing transition metal complex is reported as an efficient catalyst for Suzuki, Heck, and Sonogashira cross-coupling reactions. The protocol was also applied successfully for cyanation of aryl halides under milder operating conditions. The system tolerated the coupling of various aryl halides with alkenes, alkynes, and organoboronic acid along with the cyanation of aryl halides providing good to excellent yields of desired products.     

Oxa-Michael加成反应的研究新进展

Oxa-Michael加成反应是一类重要的反应, 经常被用于天然产物的合成, 但该反应直到近几年才被深入研究. 简要综述了oxa-Michael加成反应的研究进展.     

Tandem Hass-Bender/Henry reaction for the synthesis of dimethylnitro alcohols from benzylic halides

Dimethylnitro alcohols are constructed in a one-pot process from benzylic halides and 2-nitropropane. The use of tetrabutylammonium fluoride (TBAF) as the promoter is essential for this tandem Hass-Bender/Henry reaction to proceed.     

Boehmite@tryptophan‐Pd nanoparticles: A new catalyst for C–C bond formation

A boehmite@tryptophan‐Pd nanoparticulate catalyst was prepared by a simple, fast and convenient route. The nanomaterial was characterized using various techniques and employed as a thermally stable catalyst for Heck, Stille and Suzuki cross‐coupling reactions. Optimized conditions for these reactions are described. The catalyst could be isolated, post‐reaction, by simple filtration and recycled for several consecutive cycles without a notable change in its activity.     

温度和时间对有机合成反应影响的探讨

根据物理化学和有机合成原理,从动力学、热力学、反应机理及溶解度等各方面详细分析了反应温度和反应时间对有机合成反应的影响。通过这些分析,可以让同学们更好地在合成反应课程的学习中掌握和分析反应温度和反应时间对反应的影响。     

Acid‐Acid‐Catalyzed Tandem Reactions Driven by an Additive‐Like Component

Acid‐catalyzed tandem reactions with auto‐tandem catalysis are effective for simplifying organic synthesis. However, some of the reported reactions were established based on the use of well‐designed substrate with complex structure. In some cases, owing to the existence of a big gap between each catalytic cycle, it is hard to bind all the individual reaction steps to be a peaceful sequence. To enrich the diversity and also to strengthen the practical usefulness of the methodology developed by auto‐tandem catalysis, an additive‐like component was added to induce acid‐acid‐catalyzed tandem reaction. During the reaction, the additive‐like component acted either as an activator to increase the reactivity of the starting material or a hided reagent to enable successful transformation of the intermediate. Many novel tandem reactions were established in a one‐pot manner with the aid of this strategy. Importantly, this strategy not only allows the use of simple and commercially available chemicals as substrates, but also possesses multiple merits, such as simplifying operation, lowering waste generation and enhancing synthetic efficiency and atom‐economy. A summarization of the additive‐like component‐induced auto‐tandem catalysis with an acid catalyst was given in this review, in which many acid‐acid‐catalyzed tandem reactions were discussed. The reported additive‐like components were classified as three types: oxidative type, reductive type and neutral type depending on their mechanisms in assisting the establishment of acid‐acid‐catalyzed tandem reactions. Many examples were collected and analyzed from the viewpoints of simplifying the synthesis and manifesting their superior and distinct functionalities of the additives. A perspective of this concept was also given at the end of this review.     

钯催化的交叉偶联反应——2010年诺贝尔化学奖获奖工作介绍

钯催化的交叉偶联反应是非常实用的合成新方法.文章给出了Heck反应、Negishi反应和Suzuki反应的概念,对其反应机理作了详细的说明,并对其在复杂化合物和天然产物全合成中的应用作了评价.