三方非对称进化博弈行为分析

随着政府涉入领域以及社会合作谈判领域的增多,三方非对称进化博弈越来越多地出现在现实生活中.但目前国内外对该类型的进化博弈研究甚少,这显然不利于正确地解释和预测该类型的博弈行为.基于此,运用进化博弈论中的“复制动态”思想,对三方非对称的2×2×2进化博弈进行了渐进稳定性分析,完整地给出了其定性行为的等价定量分类和各参与主体不同情况下的稳定性策略,并且用三维立体图演示了不同策略组合的渐进趋势,从而为研究现实生活中该类型的博弈行为提供了一种理论依据.     

Recent Advances in Divergent Synthetic Strategies for Indole-Based Natural Product Libraries

Considering the potential bioactivities of natural product and natural product-like compounds with highly complex and diverse structures, the screening of collections and small-molecule libraries for high-throughput screening (HTS) and high-content screening (HCS) has emerged as a powerful tool in the development of novel therapeutic agents. Herein, we review the recent advances in divergent synthetic approaches such as complexity-to-diversity (Ctd) and biomimetic strategies for the generation of structurally complex and diverse indole-based natural product and natural product-like small-molecule libraries.     

High‐Performance Magnetic Refrigerant Featuring One‐Dimensional Gd‐O Chains and O‐Gd3 Triangles

Magnetic cooling at low temperature has attracted intensive interest in cryogenics research, which may become important as cooling medium for long‐wave photon detectors to support space exploration. Here, we report a Gd‐based quaternary magnetic refrigerant material, Gd₅BSi₂O₁₃, containing chains of face‐shared GdO₉ polyhedra and geometrically frustrated OGd₃ triangles. Magnetic measurements indicate that Gd₅BSi₂O₁₃ exhibits a large magnetocaloric effect (MCE) about 1.74 times that of the practical magnetic refrigerant GGG (−ΔS_m=67.0 J kg⁻¹ K⁻¹). We analyzed the origin of the large MCE by comparing Gd^III‐containing compounds with different structures and concentrations of Gd^III.     

高三尖杉酯碱和三尖杉酯碱的合成研究

天然药物高三尖杉酯碱和三尖杉酯碱是从三尖杉植物的叶和茎中分离得到的微量生物碱,是手性化合物。结构上,二者不仅含有一个共同的母核三尖杉碱,酯基侧链的α位也均为手性叔醇。因母核三尖杉碱和酯基侧链较大的空间位阻,两个结构片段的酯化偶联具有较大的挑战性。设计合成位阻较小的侧链中间体是酯化反应发生的关键。因此,化学家们相继合成了结构多样的α-羰基羧酸侧链以及含有杂环的侧链中间体,如四元内酯杂环侧链、四氢呋喃杂环侧链、六氢吡喃杂环侧链、七元内酯杂环侧链,并成功地完成了高三尖杉酯碱、三尖杉酯碱和同属其他活性生物碱的合成。本文基于本课题组的相关研究,根据侧链片段的构建策略和方法,综述了天然药物高三尖杉酯碱、三尖杉酯碱以及其他天然产物的合成研究。不仅总结了近几年来的新进展,还对我国老一辈的科学家们在此方面作出的贡献进行了回顾。     

高中生化学学习自我诊断能力提升策略的教学实验研究

以普通高中一年级学生为研究对象,根据前期调查研究结果,提出相应的化学学习自我诊断能力的提升策略,并开展教学实验,验证其有效性。实验表明,采用化学学习自我诊断表的方式确实有助于学生提升诊断能力,且教师的引导和学生自身层次都将影响该策略的最终成效。根据实验结果,对教师在学生化学学习过程中,引导他们使用自我学习诊断表提出相应的建议。     

绿色催化二氧化碳、炔丙醇和亲核试剂的三组分反应

近些年来,将CO₂转化为高附加值化学品受到广泛关注。其中,CO₂、炔丙醇和亲核试剂的三组分反应可用于制备用途广泛的羰基化合物,该方法具有步骤经济性、原子经济性等优点。由于CO₂分子具有热力学稳定性和动力学惰性,多数CO₂参与的化学反应在热力学上不支持。然而,CO₂、炔丙醇和双亲核试剂三组分反应是热力学有利的CO₂转化反应,实现了邻二醇或氨基醇和CO₂到环状碳酸酯以及2-噁唑啉酮的高效转化。本综述旨在于总结并讨论近年来CO₂、炔丙醇和亲核试剂三组分反应制备多种羰基化学物的主要进展。     

Concise Construction of the ACDE Ring System of Calyciphylline A Type Alkaloids by a [5+2] Cycloaddition

A concise route for construction of the ACDE ring skeleton in calyciphylline A type alkaloids was developed using an intramolecular [5+2] cycloaddition reaction of an oxidopyrylium species bearing a tetrasubstituted olefin. Key to the success of this reaction was the combination of acid and base, which accelerated the construction of this skeleton containing a spiro ring and vicinal quaternary carbon centers. The resultant tricyclic ADE ring compound was converted to an ACDE ring model through C−H oxidation and an aza-Wittig reaction.     

Optimisation of a key cross-coupling reaction towards the synthesis of a promising antileishmanial compound

During the course of a research program aimed at identifying novel antileishmanial compounds, a multi-gram synthesis of N-(trans-4-((4-methoxy-3-((R)-3-methylmorpholino)-1H-pyrazolo[3,4-d]pyrimidin-6-yl)amino)cyclohexyl)-2-methylpropane-1-sulfonamide ((R)-1) was required. This letter describes optimisation of the reaction conditions and protecting group strategy for a key Buchwald-Hartwig coupling, delivering the required quantities of (R)-1, as well as further compounds in the series.     

Assessing the emerging biorefinery sector in Canada

The biorefinery is a key concept used in the strategies and visions of many industrial countries. The potential for Canadian biorefineries based on lignocellulosic forest and agricultural residues is examined. The sector is described in terms of research interests, emerging companies, and established corporate interests. It is found that the Canadian biorefining sector currently has an emphasis on specific bioproduct generation, and the process elements required for a true sugar-based process are in the research phase. A Canadian national strategy should focus on increasing forest industry participation, and increasing collaboration with the provinces, particularly in western Canada.