A convenient method for synthesis of polyfunctional dihydropyrrole spiro-fused oxindole-2-ones via an organocatalytic tandem Michael/cyclization sequence

A new methodology was developed for the synthesis of spirocyclic oxindoles bearing polyfunctional dihydropyrrole units via an organocatalytic tandem Michael/cyclization sequence. Products bearing adjacent quaternary–tertiary stereocenters were smoothly obtained in high yields (up to 97% yield) with excellent diastereoselectivities up to >20/1.     

Palladium‐catalyzed carbonylation of quaternary ammonium halides to tertiary amides

Catalytic carbonylation of quaternary ammonium salts under anhydrous conditions was investigated using palladium catalyst. The carbonylation of tetramethylammonium iodide was chosen as a model reaction and studied systematically. Ligand‐free PdCl₂ showed efficient catalytic performance for this transformation. A palladium catalyst loading as low as 0.05 mol% was sufficient for high yield (96.9%) of N,N‐dimethylacetamide, corresponding to a turnover frequency of 242 h^?1. Under optimum conditions, several other quaternary ammonium halides were also carbonylated to corresponding tertiary amides in moderate to excellent yields. The catalytic activity of commercial palladium on activated carbon (Pd/C) catalyst was also evaluated. The Pd/C catalyst exhibited high activity for this carbonylation reaction and could be recycled six times with a slight decrease in activity. Furthermore, mechanistic considerations concerning Pd‐catalyzed carbonylation of quaternary ammonium halides were also discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

苯二胺和联苯二胺类叔芳胺的合成及发光性能的研究

N,N′-二苯基-1,4-苯二胺和N⁴,N^4'-二苯基-4,4'-联苯二胺分别与芳基溴在Pd(OAc)₂/P(t-Bu)₃催化下于120 ℃邻二甲苯溶液中反应生成苯二胺和联苯二胺类叔芳胺有机电致发光材料, 这些化合物的熔点都在300 ℃以上. 产物的结构经¹H NMR, ¹³C NMR, ¹³C (DEPT), MS (HREI和EI)表征. 用UV-Vis, PL, DSC测定了苯二胺和联苯二胺类叔芳胺化合物的发光性能.     

特丁基对苯二酚对生物柴油的抗氧化性能研究

生物柴油的氧化安定性是确保生物柴油品质的关键因素。本文采用欧盟标准(EN14214-2002),使用瑞士万通公司生产的873型生物柴油氧化安定性测定仪,采用在植物油抗氧化方面最常用、最有效的特丁基对苯二酚(TBHQ)对由地沟油、大豆油和棉籽油制成的生物柴油的抗氧化性进行了系统的定量研究。结果表明,当添加量大于0.6‰时,3种生物柴油抗氧化时间均超过国标规定的6h。TBHQ是一种理想的生物柴油抗氧化剂,对比另一种常用的抗氧化剂BHA(叔丁基对羟基茴香醚)抗氧化性能优势明显。     

Synthesis,self-assembly,and pH-responsive drug release of PHMEMA-PEG-PHMEMA ABA triblock copolymers

Abstract

A series of tertiary amine containing PHMEMA-PEG-PHMEMA ABA triblock copolymers were synthesized by atom transfer radical polymerization (ATRP) using bromine-capped poly(ethylene glycol) (Br-PEG-Br) and 2-(hexamethyleneimino)ethyl methacrylate (HMEMA) as macro-initiator and monomers, respectively. The chemical structures and molecular weights of triblock copolymers were characterized by ¹H NMR and gel permeation chromatography (GPC). The self-assembly behaviors of copolymers in different pH conditions were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Triblock copolymers self-assembled into micelles in water (pH 7.4) and the micelles disassembled at acidic pH (pH 5.0). Anticancer drug doxorubicin (DOX) was used as a drug model and physically encapsulated into polymeric micelles. The drug release of DOX-loaded polymeric micelles was pH-responsive; the drug-loaded micelles that had higher contents of tertiary amine in polymer pendant groups showed faster release speed. In addition, the drug-loaded micelles showed excellent inhibition efficacy against HeLa cells in vitro.     

Access to chiral tertiary amines via the iridium-catalyzed asymmetric hydrogenation of enamines

The asymmetric hydrogenation of N,N-dialkyl and N-alkyl-N-aryl enamines to chiral tertiary amines was studied. All the N,P-ligated iridium complexes investigated were active catalysts for the reaction, but only those with bicycle-supported oxazoline-phosphine ligands gave reasonable stereoinduction. The best catalyst produced a range of chiral tertiary amines in up to 87% ee.     

叔胺N235-PtCl6^2- -HCI萃取体系第三相中“超浓盐酸”的生成及其微乳结构

采用分子谱学及同步辐射X射线小角散射（SAXS）等表征手段,研究了三烷基叔胺（N235）莘取PtCl6^2-体系中第三相的形成及溶液微观聚集态结构的变化对PtCl6^2-萃取行为的影响．实验结果表明：萃铂有机相中第三相的形成与萃入有机相的酸和水含量的变化导致溶液结构发生变化有关：与含铂高酸度盐酸水溶液平衡后,第三相微乳水团中形成H^＋／H2O摩尔比远大于37wt％常规饱和浓盐酸的“超浓盐酸”;“超浓盐酸”微观介质内H^＋和Cl^-的大量聚集增浓对Pt离子的络合配位状态产生影响,H^＋参与了Pt离子配位状态的转变：第三相“超浓盐酸”形成后,使得微乳水团中大量存在的H^＋有可能参与调控水团中各种HmPtCl6^z＋复合络离子配位状态的相对含量,被H^＋活化的叔胺（R3NH^＋）与Pt离子的各种配位状态的匹配程度最终决定了铂在第三相中的萃取行为．     

含叔胺结构高光响应性香豆素衍生物的设计合成

以环氧氯丙烷为桥接, 将具有较强给电子能力的芳叔胺(ATA)结构引入香豆素衍生物C分子中, 通过芳叔胺结构的光化学促进作用加速香豆素基元的光二聚反应. 用紫外(UV)和荧光(FL)光谱等手段对该香豆素衍生物进行表征. 结果表明, 芳叔胺结构的引入可有效增强香豆素基元在260-400 nm之间的吸收. 紫外点光源光二聚反应实验表明, 芳叔胺结构的引入使香豆素基元的光响应性能得以大幅增强, 在相同光照条件下, 其在匀速反应区间内对光照时间的依赖性的斜率高达6.47, 光二聚反应程度达到80%时所需光照时间仅为29 s.     

Cleavage of Carbon Disulfide by n-Propyldiphenylphosphine and Nickel(II) Bromide

Carbon disulfide is cleaved by n-propyldiphenylphosphine and nickel(II) bromide in a one-step process, to form two unprecedented complexes: orange, [Ni(S₂C₂(PⁿPrPh₂)₂)Br(PⁿPrPh₂)]Br⋅CS₂ ( 1 ) and purple [Ni{η²-SC(PⁿPrPh₂)₂}Br(PⁿPrPh₂)]Br⋅0.5CS₂ ( 2 ). Orange ( 1 ) contains a dithiolene-related ligand that results from carbon–carbon bond formation, while purple ( 2 ) contains a remarkable ligand in which two n-propyldiphenylphosphine molecules have added to a carbon atom of a CS unit that is coordinated to nickel.