Diastereoselective synthesis of multisubstituted isoindolines via Sequential Ugi and aza-Michael addition reaction

A new efficient and diastereoselective synthesis of multisubstituted isoindolines with two stereogenic centers via sequential Ugi/aza-Michael addition reaction was developed. Ugi-3CR of aldehydes 1, amines 2 and isocyanates 3 in the presence of catalytic amount of H₃PO₄ produced intermediates 4, which were then transformed to isoindolines 5 with good 1,3-trans diastereoselectivity in the presence of K₂CO₃ by intramolecular aza-Michael addition. Sequential Ugi-azide and aza-Michael addition reaction of aldehydes 1, amines 2 and trimethylsilyl azide 6 also produced 4-tetrazolyl substituted isoindolines 8 with good 1,3-trans diastereoselectivity in the presence of potassium carbonate.     

Inexpensive Hole‐Transporting Materials Derived from Tröger's Base Afford Efficient and Stable Perovskite Solar Cells

The synthesis of three enamine hole‐transporting materials (HTMs) based on Tröger's base scaffold are reported. These compounds are obtained in a three‐step facile synthesis from commercially available materials without the need of expensive catalysts, inert conditions or time‐consuming purification steps. The best performing material, HTM3, demonstrated 18.62 % PCE in PSCs, rivaling spiro‐OMeTAD in efficiency, and showing markedly superior long‐term stability in non‐encapsulated devices. In dopant‐free PSCs, HTM3 outperformed spiro‐OMeTAD by a factror of 1.6. The high glass‐transition temperature (T_g=176 °C) of HTM3 also suggests promising perspectives in device applications.     

UPLC-Q/TOF-MS coupled with multivariate analysis for comparative analysis of metabolomic in Dendrobium nobile from different growth altitudes

Dendrobium nobile alkaloids (DNLA) and glycosides are the main active components extracted from Dendrobium nobile Lindl. (D. nobile) used for thousands of years in China. The pharmacological effects of the above chemical components are significantly different. D. nobile is mainly grown at an altitude ranging from 230 to 800 m in Chishui City, Northwest Guizhou Province. However, it is unclear whether the metabolite in D. nobile is influenced by the planting altitude. Hence, to reveal the different metabolite in D. nobile cultivated at the altitude of 336 m, 528 m, and 692 m, ultra-high performance liquid chromatography with Q/TOF-MS couple with multivariate analysis were developed. Using the orthogonal partial least squares-discriminant analysis, 19 different metabolites were discovered and then tentatively assigned their structures as alkaloids and glycosides by comparing mass spectrometry data with in-house database and literature. Moreover, the result of semiquantitative analysis showed the content of dendrobine that was belonged to alkaloids significantly increased at the altitude of 692 m, whereas the content of glycosides demonstrated an accumulation trend at the altitude of 528 m. The results could provide valuable information for the optimal clinical drug therapeutics and provide a reference for quality control.     

AN OPTIMAL INVESTMENT／CONSUMPTIONPROBLEM WITH HIGHER BORROWING RATE

In this paper, optimal investment and consumption decisions for an optimal choiceproblem in infinite borizon are considered, for an investor who has available a bank account anda stock whose price is a log normal diffusion. The bank pays at an interest rate r for any de-posit, and takes at a larger rate / for any loan. As in the paper of Xu Wensheng and ChenShuping in JAMS(B), where an analogous problem in finite horizon is studied, optimal strategies are obtained via Hamilton-Jacobi-Bellman (ladE) equation which is derived from dynamic c1-programming principle. For the specific HARA case, i.e. U(t,c)=e^-βtc^1-R/1-R, this paper getsthe optimal consumption and optimal investment in the form of c^‘1 =β -^-g/Rwi and π^‘1= b -- γ / Rσ^2wr, with γ1,=max{γ,min{γ‘,b--Rσ^2‘} },^-g=(1--R)[γ (b-γ)^2/2Rσ^2]. This result coincides with the classical one under condition γ‘ ≡γ.     

Oligonucleotides Containing 7‐Deaza‐2′‐deoxyinosine as Universal Nucleoside: Synthesis of 7‐Halogenated and 7‐Alkynylated Derivatives,Ambiguous Base Pairing,and Dye Functionalization by the Alkyne–Azide ‘Click’ Reaction

Oligonucleotides containing 7‐deaza‐2′‐deoxyinosine derivatives bearing 7‐halogen substituents or 7‐alkynyl groups were prepared. For this, the phosphoramidites 2b – 2g containing 7‐substituted 7‐deaza‐2′‐deoxyinosine analogues 1b – 1g were synthesized (Scheme 2). Hybridization experiments with modified oligonucleotides demonstrate that all 2′‐deoxyinosine derivatives show ambiguous base pairing, as 2′‐deoxyinosine does. The duplex stability decreases in the order C_d>A_d>T_d>G_d when 2b – 2g pair with these canonical nucleosides (Table 6). The self‐complementary duplexes 5′‐d(F⁷c⁷I‐C)₆, d(Br⁷c⁷I‐C)₆, and d(I⁷c⁷I‐C)₆ are more stable than the parent duplex d(c⁷I‐C)₆ (Table 7). An oligonucleotide containing the octa‐1,7‐diyn‐1‐yl derivative 1g , i.e., 27 , was functionalized with the nonfluorescent 3‐azido‐7‐hydroxycoumarin ( 28 ) by the Huisgen–Sharpless–Meldal cycloaddition ‘click’ reaction to afford the highly fluorescent oligonucleotide conjugate 29 (Scheme 3). Consequently, oligonucleotides incorporating the derivative 1g bearing a terminal C?C bond show a number of favorable properties: i) it is possible to activate them by labeling with reporter molecules employing the ‘click’ chemistry. ii) Space demanding residues introduced in the 7‐position of the 7‐deazapurine base does not interfere with duplex structure and stability (Table 8). iii) The ambiguous pairing character of the nucleobase makes them universal probes for numerous applications in oligonucleotide chemistry, molecular biology, and nanobiotechnology.     

正十二烷醇与环氧乙烷的加成反应动力学研究──最佳反应时间的确定

正十二烷醇与环氧乙烷的加成反应动力学研究──最佳反应时间的确定张仁权,张维冰,李葵英,王万兴（齐齐哈尔轻工学院化工系,齐齐哈尔,１６１００６）关键词正十二烷醇聚氧乙烯醚,碱催化,聚合度在工业生产中脂肪醇与环氧乙烷的加成反应多采用ＫＯＨ和ＮａＯＨ等强碱...     

HIGHER ORDER THEORY ACROSS A THREE DIMENSIONAL AXIALLY-SYMMETRICAL CURVED SHOCK NEAR THE STAGNATION POINT

The next order conditions across a three-dimensional curved shock near stagnationpoint have been established,including the effects of heat conduction,viscosity and the shockstructure.These shock conditions involve the local shock curvature in addition to its localinclination.Explicit results have been obtained for the correctional formulations in themass flux across the shock,the stagnation enthalpy,the tangential component of velocityand the normal component of momentum flux.     

计算股市的基本方程、理论和原理(Ⅰ)——基本方程

本文采用网络模型和类似于固体力学的方法论来研究计算股市。建立四个基本的联立方程,即:利率-流通量方程;股票买入、卖出方程;股价变化率方程;以及利率、股价及股价变化率方程。文中着重讨论利率-流通量方程的解及其简单应用,包括时间离散化时股市网络用Banach收缩映射定理证明最终趋向平衡状态,以及银行减息引起资金流动按指数型式衰减等。