A New Route for Synthesis of Entecavir

A new economical synthetic route of the key intermediate 6. The synthesis of a modified Mitsunobu reaction. of entecavir was presented, involving the preparation 6 was conveniendy achieved in good overall yield by a modified Mitsunobu reaction.

A NEW ROUTE FROM HETEROAROMATIC BORON COMPOUNDS TO CORRESPONDING KETONES VIA DICHLOROCARBENE INSERTION UNDER PHASE TRANSFER CONDITIONS

The reactions of tri-2-benzofuranylborane or aminoethyl di-2-thienylborinate and 2-thienylphenylborinate with dichlorocarbene generated in situ from chloroform under phase transfer conditions were explored as a new route for the preparation of heteroaromatic ketones. It was found that a good yield of the ketones can be obtained by solid-liquid system.

Mosaic crystals leading a new route to achieve ultrahigh thermoelectric performance

Solid-state thermoelectric technology uses electrons or holes as the working fluid for heat pumping and power generation.Adopting the technology in harvesting solar heat,converting waste industrial heat into electricity,and pumping out operational heat has tremendous potential in solid-state electronics applications.A combination of highly efficient electronic transport and low heat conductivity is a prerequisite for excellent thermoelectric performance.As these two requirements are substantially orthogonal,their synchronous realization is difficult in practice,hindering the commercial use of thermoelectricity[1,2].Scientists from the Shanghai Institute of Ceramics,Chinese Academy of Sciences,in collaboration with scien-

A New Route for the Rapid Synthesis of Metal–Organic Frameworks at Room Temperature

Rapid synthesis of metal–organic frameworks(MOFs),especially high-valence MOFs at roomtemperature without external energy,is a challenging topic.In this work,a stable radical solution has been discovered.Various MOFs with versatile metal nodes and ligands were rapidly synthesized at room temperature in the absence of external energy.Especially,MOFs with conjugated ligands achieved instantaneous architecture(in less than 1 s)and quantitative yield.Radicals in the solution play a crucial role in the accelerated kinetics,and the new radical route paves a cyclic pathway for the MOF synthesis.The mechanism has been thoroughly investigated by electron paramagnetic resonance,in situ proton nuclear magnetic resonance,X-ray absorption spectra,in situ small-angle X-ray scattering-wide-angle X-ray scattering,and density functional theory calculations.

Kenya Airways Establishes New Routes to Ouagadougou

Kenya Airways,one of the best and most respected airline companies in Africa, recently officially announced its intent to fly to Ouagadougou, capital of Burkina Faso, starting July 15,

CHARTING A NEW ROUTE TO THE ACHIEVEMENT OF NATIONAL STANDARDS: BRINGING THE CLASS TO LIFE

Introduction In this article we discuss making use of applied linguistic theory, as the means of achieving national standards at tertiary level. We contest that methods now widely in use at colleges and universities are insufficient to reach modern nationwide targets. We suggest modifications in teaching approach and present ideas for supplementing and enlivening existing materials or replacing them. Much of the article is drawn from our converging experiences both as a Chinese university teacher of English from one aspect and as an English EFL specialist from another. We speak jointly from the ’chalkface’ and wish to share our views and be provoked into seeking solutions to the new challenges for Chinese EFL inherent in targets set by the national standards.

A new route for the synthesis of ω-acyl carboxylic acids

A new method for synthesis of ω-acyl carboxylic acids is described. Photooxygenation of cyclic silyl enol ethers sensitized by 9,10-dicyanoanthracene (DCA) provided ω-acyl carboxylic acids in modest to good yields.

A new route to prepare the mixed oxo-ethylidynecapped trinuclear tungsten(Ⅳ)cluster and the crystal structure of H_2Na_3[W_3O(CCH_3)(O_2CCH_3)_6(H_2O)_3][H_2W_(12)O_(40)]·13.5H_2O

The synthesis and the structural characterization of the title compound HNa[WO（CCH）-（OCCH）（HO）][HWO]·13.5 HO are described.It is known that the mixed oxo-ethylidyne-capped tritungsten cluster can be obtained by Zn dust reduction of NaWO·2HO in acetic anhydride.The title compound has been characterized by X-ray diffraction,UV/VIS andH NMR spectra.The tungsten atoms in the cluster cation and anion are in the oxidation states of W（IV）and W（VI）respectively.The crystal is rhombohedral with the space group R32,a=17.058（3）,c=49.665（9）,γ=120°,V=12516（9）,Z=6,final R=0.037 for 2071 reflections with I≥3σ（I）.Boththe cluster cation and anion have a Csymmetry.The important interatomic distances in angstroms forthe cluster cation are:W—W,2.730（2）;W—μ-O,2.00;W—O（carboxyl）,2.12;W—O,2.18（2）.

A NEW SYNTHETIC ROUTE TO α-DAMASOONE

A new synthetic route to α—damascone (4) starting from citral is described-The synthesis features allylatioa of α—cyclocitral (1) with allylic bromide in the presence of tin powder to give the crucial intermediate 1—(2',6',6'—trimethylcyclo— hexen —2'—yl)—3—buten —1—ol(2a) and (2b) in a combined yield of 70%.

A New Synthetic Route to Di-η~5-Cyclopentadienyl Ytterbium(Ⅱ)Tetrafuranate (η~5-C_5H_5)_2Yb(THF)_2 and Its Crystal Structure

In recent years,the organometallic ehemistry of the lanthanide metals in low oxidation states has beenactively investigated.The synthesis of the low一valent lanthanide eomPlexes has the signifieant meanings ontheory and praeti

New Ad Hoc QoS Multicast Routing Protocol

The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the frequent changes of network topology caused by nodes movement. An Ad hoc QoS Multicasting (AQM) protocol can solve this problem by previously reserving the neighbor nodes for tracking resource availability. By considering QoS restrictions of transport delay, loss ratio, bandwidth requirement, delay jitter, and throughout, and by finding the adaptive routing, the AQM protocol can obviously improve the efficiency of multicastsession. The results of network simulation show that QoS is essentially applicable to Ad hoc networks.

New bubble-exfoliation route to prepare high-quality graphene with high yield

With the support by the National Natural Science Foundation of China and the Ministry of Science and Technology of China,the research team led by Prof.Ding Guqiao(丁古巧)and Dr.He Peng(何朋)at Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,achieved

An improved and practical route for the synthesis of enzalutamide and potential impurities study

An improved and practical synthesis of enzalutamide was accomplished in five steps.Starting from 4-bromo-2-fluoro-benzonic acid,a methyl esterification,Ullmann ligation,methyl esterification,ring closing reaction and final methyl amidation provided the target in 35% total yield with 99.8% purity.Five identified impurities were also synthesized.This efficient and economical procedure avoids the use of highly toxic reagents and multiple recrystallization operations,which is suitable for further industrialization.

A new and efficient method for the synthesis of rocuronium bromide

Rocuronium bromide has been used as an aminosteroid non-depolarizing neuromuscular blocker and muscle relaxant.In this work,a new and efficient route for preparing a key intermediate 2β-（4-morpholinyl）-16β-（1-pyrrolidinyl）-5α-androstan-3α,17β-diol（6） was developed through a ring-opening of epoxide followed by introducing and pyrrolidine.Compound 6 can easily provide rocuronium bromide and the overall yield of compound 6 in 5 steps increased to 57.8%,which was higher than currently reported methods.Extraordinarily,this method would avoid the generation of disubstituted impurities E and F which are difficult to remove.