电催化4-喹诺酮和二烃基二硒醚的交叉脱氢偶联反应

发展环境污染少的可持续绿色合成反应是绿色化学的主要目标之一.均相反应是制备高附加值化学品的重要方法,但是该类反应普遍存在催化剂和有机溶剂不易回收利用、产品分离纯化成本高、污染重的问题.发展兼具催化剂和溶剂易循环使用及产品易分离纯化的高附加值化学品的绿色制备方法具有重要的研究意义.4-喹诺酮是一类重要的氮杂环化合物,广泛...     

Visible-Light Photosynthesis of CHF2/CClF2/CBrF2-Substituted Ring-fused Quinazolinones in Dimethyl Carbonate

With eco-friendly and sustainable CO₂-derived dimethyl carbonate as the sole solvent, the visible-light-induced cascade radical reactions have been established as a green and efficient tool for constructing various CHF₂/CClF₂/CBrF₂-substituted ring-fused quinazolinones.     

Two new flavan-flavanones from Sarcandra hainanensis

Chemical study of the whole plants of Sarcandra hainanensis yielded two new biflavonoids with a flavan-flavanone skeleton, sarcandrone C (1), D (2) and 6 known compounds (3-8). Structures were elucidated on the basis of NMR spectroscopic methods.     

Simple and Effective Synthetic Approach to Chiral 2-Amino-4-piperidinyl Pyridine Derivatives

A facile way has been developed to provide a series of novel chiral N-(4-(piperidin-1-yl)pyridin-2-yl)amide derivatives as potential stereoselective catalysts. The key intermediate, 2-amino-4-piperidinyl pyridine, was obtained by nucleophilic substitution of 2-amino-4-chloropyridine with piperidine in good yields (up to 96%). The total control of enantioselectivity was obtained for the synthesis of L-proline and (R)-1,1′-bi(2-naphthol) derivatives.     

喹啉氧基乙酰胺的Li(I)/Na(I)配合物及其高氯酸盐的结构和荧光性质

合成并通过X射线单晶衍射表征了配合物[Li（L）₂]ClO₄（1）和[Na（L）₂]ClO₄（2）的结构（L为2-（5-氯-喹啉-8-基氧基）1-吡咯烷酮）。单晶衍射结果表明,配合物1与2同构,金属离子与来自2个酰胺配体L的N₂O₄电子供体配位,形成扭曲的八面体配位构型。此外,还测定了配体高氯酸盐（HL）ClO₄·H₂O的结构,并详细研究了3个化合物的荧光性质。     

Time Rates of Hill's Strain Tensors

Based on Hill's principal components formulae, two kinds of basis-free time rate formulae for Hill's strain tensors are proposed in this paper, which are obtained for the cases of distinct stretches, double coalescence and triple coalescence. Furthermore, relations between the coefficients in the representation for the strain tensor and its time derivative are disclosed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Two new eudesmanes from <Emphasis Type="Italic">Inula helenium</Emphasis>

Two new eudesmanes, 1α-hydroxy-11,13-dihydroisoalantolactone (1), 3α-hydroxy-11,13dihydroalantolactone (2), and one known compound were isolated from the roots of Inula helenium. Their structures were established on the basis of spectral evidence.     

Gibbs-Appell' s equations of variable mass controllable mechanical systems in terms of quasi-velocities and quasi-accelerations

In this paper, the Gibbs-Appell' s equations of the nonholonomic controllable mechanical systems with variable mass in terms of quasi-velocities and quasi-accelerations are obtained, and the application of the new equation is illustrated by an example.The project was Supported by the Heilongjiang Natural Science Foundation