Efficient glycosylation with glycosyl ortho-allylbenzoates as donors

Glycosylation reactions are significant as they provide access to model compounds that are useful for elucidating biochemical pathways. Herein, we describe the development of glycosyl ortho-alkynylbenzoates as novel, bench-top stable, and readily available glycosyl donors. Glycosylation is promoted by inexpensive trimethylsilyl triflate (TMSOTf) in combination with N-iodosuccinimide (NIS) under mild reaction conditions; hence, the novel glycosyl donors are promising reagents for the synthesis of glycosides.     

NIS-promoted multicomponent reaction of 2-aminopyridines with aldehydes and nitromethane for the synthesis of 3-nitroimidazo[1.2-a]pyridines

An efficient synthesis of 3-nitroimidazo[1,2-a]pyridines has been developed via N-iodosuccinimide (NIS)-mediated multicomponents reaction of 2-aminopyridines, aldehydes, and nitromethane under metal-free conditions. This protocol has many advantages such as broad substituent scope, mild and eco-friendly conditions, high step economy, and good yields.     

不同类型土壤总氮的近红外光谱技术测定研究

该研究从江苏、河南、山西、河北、吉林采集部分表层土壤,并在山西河北两地采集表下层土壤,经前处理后通过近红外光谱仪扫描得到光谱图,用传统开氏法测得其总氮,运用OPUS软件建立了土壤总氮和光谱图之间的数学模型,并初步探讨了模型的应用范围。结果表明：各地区表层土壤建立的模型良好,交叉检验的均方根误差均在0.01%以内,相关系数平均在0.85以上,并且该模型能够很好地定量分析同一采样范围内表层和表下层的土壤总氮,定量分析的均方根误差基本在0.01%以内,相关系数在0.80左右;可能受土壤类型的影响,该模型在地区之间的运用具有一定的局限性;从各地区随机取出部分数据作为一个新的集合建立的综合模型良好,其交叉检验的均方根误差和相关系数分别为0.010 2%和0.985 6,并且该模型能很好地预测各地区的土壤总氮。     

NIS-promoted guanylation of amines

An efficient NIS-promoted guanylation reaction is described. This procedure allows the guanylation of primary and secondary amines through the reaction with di-Boc-thiourea and di-Boc-S-methylisothiourea, respectively. We demonstrated that the use of NIS compares favorably with existing methods and is an attractive alternative to heavy metal or Mukayama’s reagent activation.     

ESS,NIS and GIS for multi‐player matrix game in single population

In this paper, we distinguish the concept of global invader strategy (GIS) from that of neighborhood invader strategy (NIS), and discuss the concepts and the properties of ESS, NIS and GIS and relationship among them in the scenario of multi‐player matrix game. We show that a GIS is always an ESS and GIS is unique for any multi‐player. We also show that NIS is equivalent to ESS for pairwise game and there are some results in multi‐player game different from those in pairwise game. Copyright © 2009 John Wiley & Sons, Ltd.     

d(x2-y2)+idxy混合波正常金属/绝缘层/超导体结中的隧道谱

考虑界面粗糙散射,在Blonder-Tinkham-Klapwijk(BTK)理论框架下,通过求解Bogoliubov-de-Gennes(BdG)方程,分别计算T=0K和有限温度下,d_(x²-y²)+id_xy混合波正常金属绝缘层超导体结中的准粒子输运系数和隧道谱.研究表明:隧道谱中的电导峰的劈裂程度强烈地依赖于d_xy波分量的强度、超导体的晶轴方位和界面粗糙强度,而温度的升高能压低电导峰. 关键词： NIS结 (x²-y²)+id_xy混合波超导体')" href="#">d_(x²-y²)+id_xy混合波超导体 隧道谱     

Portable laser‐heating system for diamond anvil cells

The diamond anvil cell (DAC) technique coupled with laser heating has become the most successful method for studying materials in the multimegabar pressure range at high temperatures. However, so far all DAC laser‐heating systems have been stationary: they are linked either to certain equipment or to a beamline. Here, a portable laser‐heating system for DACs has been developed which can be moved between various analytical facilities, including transfer from in‐house to a synchrotron or between synchrotron beamlines. Application of the system is demonstrated in an example of nuclear inelastic scattering measurements of ferropericlase (Mg_0.88Fe_0.12)O and h.c.p.‐Fe_0.9Ni_0.1 alloy, and X‐ray absorption near‐edge spectroscopy of (Mg_0.85Fe_0.15)SiO₃ majorite at high pressures and temperatures. Our results indicate that sound velocities of h.c.p.‐Fe_0.9Ni_0.1 at pressures up to 50 GPa and high temperatures do not follow a linear relation with density.     

N‐Iodosuccinimide: A Highly Effective Regioselective Reagent for Iodoesterification of Alkenes

A rapid, convenient, and efficient method has been achieved for regioselective iodoesterification of alkenes with aliphatic and aromatic acids, and protected amino acids in the presence of N‐iodosuccinimide (NIS) in nearly quantitative yields. Optically enriched iodohydrins have been achieved by LiAlH₄ (LAH) reduction of diastereoisomeric iodo esters.