Chemoselective N-nitrosation of secondary amines under heterogeneous and mild conditions via in situ generation of HNO_2

A wide variety of secondary amines are chemoselectively subjected to N-nitrosation reaction with treatment of citric acid and NaNO2 in the presence of wet SiO2 （50%, w/w） in dichloromethane at room temperatture under heterogeneous conditions. The Nnitrosation method is very simple and products can be easily isolated with good to high yields.

Mercurous Chloride Catalyzed Mannich Condensation of Terminal Alkynes with Secondary Amines and Aldehydes

Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.

Tri-n-butylphosphane catalyzed ring opening of aziridines with secondary amines

Ring opening of aziridine with dialkyl amine took place readily in the presence of catalytic amounts of tri-n-butylphosphane （10 mol%） in the mixture of CH3CN/H20 （10：1）, giving corresponding vicinal diamines in mediate to high yields （58-95%） with good regioselectivitie, while aromatic secondary amine could not react under the same conditions. Tri-n-butylphosphane exhibited different catalytic selectivity to amines from Lewis acid catalysts.

Conjugate Additions of Secondary Amines and Water to Allenyl Perfluoroalkyl Sulfones

Preparation of allenyl perfluoroalkyl sulfones from perfluoroalkyl sulfinyl chlorides and their reactions with secondary amines and water were studied. At room temperature secondary amines reacted readily with allenyl perfluoroalkyl sulfones to give the corresponding enamine adducts, which underwent rearrangement to afford conjugate enamines in refluxing toluene. Good diastereoslectivities were observed in the addition of diethylamine to 7-ethyl-7-methylallenyl perfluoroalkyl sulfones. In refluxing acetonitrile, water could also undergo the similar addition with allenyl perfluoroalkyl sulfones.

Practical reduction of imines by NaBH_4/alumina under solvent-free conditions:An efficient route to secondary amine

Sodium borohydride supported on alumina reduces imines to the corresponding secondary amines in high to excellent isolated yields under solvent-free conditions. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogen, nitro, and cyano groups.

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

The influence of some ketones on the formation of symmetrical secondary amine N, N-bis-(3, 4-dimethoxyphenylethyl)amine 1 were discussed and a new method For preparing 1 was described.

Asymmetric Photocatalyzed Addition of Cyclic Ammes to the Chiral 5-(l)-Menthyloxy-2(5H)-furanone

The benzophenone-initiated photoaddition of N-methyl ammes 2 to the chiral synthon1 proceeds in a regiospecitlc and highlyr stereocontrolled thshion to give the C-C photoadductscontaining a ne\viy stereogenic center 3a-3c. The enantiomerically pure N-C photoadducts, aminobutenolides 5a-5c have been obtained from the enantioselective photoaddition of secondary cyclicammes 4 with the chiral synthon 1 under the same conditions.

农产品中阿维菌素QuEChERS测定方法研究

实验研究了农产品中阿维菌素Qu ECh ERS测定方法,样品通过乙腈震荡提取,丙基乙二胺(primary secondary amine sorbent,PSA)、十八(烷)基硅烷C18(octadecyl silane,ODS C18)简称C18、多壁碳纳米管(multi walled carbon nanotubes,MWCNTs)净化,过滤膜上机检测。结果表明,当PSA、C18、CNT用量分别为0.5 g,1 g,0.03 g时,净化效果最好,回收率高。回收率在80%~120%之间,可以达到检测要求,阿维菌素检出限为0.02 mg/kg,RSD小于10%,满足实验要求。

Microalgae wet extraction using N-ethyl butylamine for fatty acid production

Microalgae are considered a promising feedstock for the production of food ingredients, cosmetics, pharmaceutical products and biofuels.The energy intensity of drying and cell breaking of algae and solvent recovery afterwards hindered the route of algae biorefinery. In this work the influences of freeze drying and cell breaking to the extraction efficiency of crude lipid yield and fatty acid yield were investigated. Results showed that drying and cell breaking are not necessary for N-ethyl butylamine extraction, because good yields were obtained without. Crude lipid yield and fatty acid yield using N-ethyl butylamine were comparable with Bligh & Dyer extraction, making N-ethyl butylamine a candidate for further development of an energy efficient lipid extraction technology for non-broken microalgae.

Protecting-group-free amination of halogenated nitrobenzaldehyde with palladium catalyst

"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups.

Occurrence of selected aliphatic amines in source water of major cities in China

The formation of toxic nitrogenous disinfection byproducts （N-DBPs）, such as nitrosamines, halonitromethanes and haloacetonitriles, from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health. This study revealed the occurrence of 17 aliphatic amines, some of which have been confirmed to be the precursors of N-DBPs, in source water across China. A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples. In total, 37 source water samples from the capital cities of 20 provinces were collected for the survey. Among the 17 amines, 14 were detected with an average frequency of detection of 36%. The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine （100%, 24.82 μg/L）, methylamine （78%, 0.92 μg/L）, N-methylethylamine （70%, 8.84 μg/L）, propylamine （59%, 10.69 μg/L）, diethylamine （54%, 3.76μg/L）, N-methylbutylamine （35%, 3.07 μg/L）, N-ethylpropylamine （35%, 0.52μg/L）, and piperidine （32%, 2.35 μg/L）. This is the first large scale survey of the aliphatic amines occurrence in source water in the world. The wide presence of nitrosamine precursors like dimethylamine, N-methylethylamine and diethylamine, and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.

Oxidation of diclofenac by permanganate: Kinetics, products and effect of inorganic reductants

The large consumption and discharge of diclofenac(DCF) lead to its frequent detection in surface water and groundwater, posing great threats to humans and ecosystems. This study explored the oxidation kinetics of DCF by permanganate(Mn(Ⅶ)), and expounded the underlying reason for the unusual p Hdependency that was unclear in previous studies. The kinetics of DCF analogues(i.e., aromatic secondary amines) by Mn(Ⅶ) oxidation were comparatively investigated. Then, a tentative kinetic model involving the formation of an intermediate between Mn(Ⅶ) and DCF or its analogues was proposed to fit the p H-rate profile. Since DCF contained two chloro groups, and a carboxyl group which could be ionized by negative electrospray ionization, a precursor ionization scanning approach was used for the first time for detection of N-containing chlorinated oxidation products. New degradation pathways of DCF containing ring opening, carboxylation, carbonylation, electrophilic addition, hydroxylation and dehydrogenation were proposed based on the identified oxidation products. Moreover, it was demonstrated that the introduction of various reducing agents such as Mn(Ⅱ), Fe(Ⅱ) and bisulfite significantly improved the oxidation kinetics of DCF by Mn(Ⅶ). The positive effects of Mn(Ⅱ) and Fe(Ⅱ) were mainly attributed to the accelerated formation of MnO_(2)that acted as a catalyst or co-oxidizer contributing to DCF degradation. The presence of bisulfite caused two-stage kinetics, where a sharp drop of DCF concentration followed by a slowdown of DCF removal. In the first stage, potent reactive manganese species(e.g., Mn(Ⅲ), Mn(V), and Mn(VI)) and sulfate radical were generated during reaction of bisulfite with Mn(Ⅶ), whereas bisulfite was depleted fast due to excess Mn(Ⅶ) concentrations and the system became the Mn(Ⅶ)/MnO_(2)system in the second stage. These results provide new insight into reaction mechanism of DCF with Mn(Ⅶ)as well as propose a feasible strategy for enhancing the treatment of DCF contaminated water by Mn(Ⅶ).

Amination of electron deficient aryl chlorides promoted by nano sized Mg(OH)_2 under transition metals free condition

This paper presents the amination reactions of electron deficient aryl chlorides promoted by Mg（OH）_2 without transition metals. Only using stoichiometric amount of nano sized Mg（OH）_2,good to moderate isolated yields could be achieved in N-methylpyr-rolidone （NMP） after 24 h at 150℃.

Stereoselective Synthesis of Functionalized 1,3-Dienes in Water

An efficient synthesis of functionalized 1,3-dienes via one-pot reactions between dialkyl acetylenedicarboxylates, 1,3-dicarbonyl compounds and secondary amines in water as the solvent is described. The mild reaction condition high yields and the new products are advantages of our method.

Organocatalytic asymmetric [3+3] annulation of isatin N,N’-cyclic azomethine imines with enals:Efficient approach to functionalized spiro N-heterocyclic oxindoles

An unprecedented chiral secondary amine-catalyzed [3+3] annulation of isatin N,N’-cyclic azomethine imines with α,β-unsaturated aldehydes was developed.This strategy allowed the construction of structurally novel spiro N-heterocyclic oxindole derivatives in good yields(up to 91%) and good to excellent enantioselectivities(up to>99% ee),albeit with modest diastereoselectivities(up to 3.1:1 dr).