利用新颖高效气体发生装置以氯气氧化法制备高锰酸钾实验设计及效果*

基于一种新颖高效气体发生装置,设计了以氯气为氧化剂,理论产率接近100%的将锰酸钾高效转化为高锰酸钾的实验方案。实验结果表明:使用本设计制备高纯度高锰酸钾,既可保证高锰酸钾的理论转化率,减少歧化反应副产物对纯度的影响,同时得到的副产品次氯酸钠及氯水可用做无机教学实验的基础试剂,符合“循环经济”指导思想。     

相对性区域创新指数与经济周期挖掘

提出了一类新的相对性区域创新指数,并采用世界专利申请数据对其进行了具体计算.基于区域创新同经济发展水平之间的超线性关系,该指数消除了经济发展水平对创新能力的影响,可以实现对不同发展水平的经济体之间进行有效的创新能力横纵对比.该创新指数尽管极其简单,却揭示出一系列迥异于传统认知的现象,例如中国大陆地区的技术创新能力在1980年代就已经位居世界前列.采用该指数,不但可以在较高水平上解释世界各国的经济增长,还发现它同经济增长率之间的相关性存在一个20年的经济周期.这些结果显示,该指数作为一个单一性指标,以极小的数据依赖就实现了较高程度的解释性,不但重新定位了世界各经济体的创新能力,对深入理解创新同经济发展之间的关系提供了新的角度,而且暗示着这类相对性经济指标的发展潜力与应用空间.     

Nucleophilic and Electrophilic Activation of Non‐Heteroaromatic Amides in Atom‐Economical Asymmetric Catalysis

Recent advances in catalytic asymmetric carbon–carbon bond‐forming reactions of non‐heteroaromatic amide substrates are highlighted. Among carbonyl compounds, amides have received limited attention in catalytic asymmetric transformations mainly owing to their lower reactivity. Amides are reluctant to form enolates for nucleophilic addition, and α,β‐unsaturated amides exhibit diminished electrophilicity at the β‐carbon. Recent advances in asymmetric catalysis rendered these amides amenable to enantioselective reactions with perfect atom economy, producing synthetically useful chiral building blocks. This Minireview summarizes recent developments in the field.     

奖惩机制下闭环供应链非正规渠道社会效应研究

针对闭环供应链非正规渠道在促进资源回收再利用的同时又对环境造成二次污染的情况,给出资源回收当量指标以综合考量渠道资源回收和再造污染效应,利用数学优化和数值仿真方法对比分析存在政府奖惩机制下非正规渠道的经济效应和资源回收效应,获得了非正规渠道积极社会效应的通用定理以及不同再造回收率和奖惩强度下非正规渠道社会效应的特点,给出了政府治理非正规渠道的参考建议和分析方法。     

Welfare Cost of Model Uncertainty in a Small Open Economy

This paper extends the canonical small open-economy real-business-cycle model, when considering model uncertainty. Domestic households have multiplier preferences, which leads them to take robust decisions in response to possible model misspecification for the economy’s aggregate productivity. Using perturbation methods, the paper extends the literature on real business cycle models by deriving a closed-form solution for the combined welfare effect of the two sources of uncertainty, namely risk and model uncertainty. While classical risk has an ambiguous effect on welfare, the addition of model uncertainty is unambiguously welfare-deteriorating. Hence, the overall effect of uncertainty on welfare is ambiguous, depending on consumers preferences and model parameters. The paper provides numerical results for the welfare effects of uncertainty measured by units of consumption equivalence. At moderate (high) levels of risk aversion, the effect of risk on household welfare is positive (negative). The addition of model uncertainty—for all levels of concern about model uncertainty and most risk aversion values—turns the overall effect of uncertainty on household welfare negative. It is important to remark that the analytical decomposition and combination of the effects of the two types of uncertainty considered here and the resulting ambiguous effect on overall welfare have not been derived in the previous literature on small open economies.     

不对称烯丙基化反应合成含有三苯胺核心单元的荧光非天然氨基酸衍生物

报道了一种钯催化噁唑酮和烯丙醇的不对称烯丙基化反应合成相应的三苯胺核心非天然氨基酸化合物的方法.反应收率高达95%,对映选择性过量值最高为97%ee.该反应操作简单,条件温和,原子经济性好,水为唯一副产物.     

C–H Activation and Alkyne Annulation via Automatic or Intrinsic Directing Groups: Towards High Step Economy

Direct transformation of carbon–hydrogen bond (C–H) has emerged to be a trend for construction of molecules from building blocks with no or less prefunctionalization, leading high atom and step economy. Directing group (DG) strategy is widely used to achieve higher reactivity and selectivity, but additional steps are usually needed for installation and/or cleavage of DGs, limiting step economy of the overall transformation. To meet this challenge, we proposed a concept of automatic DG (DG^auto), which is auto‐installed and/or auto‐cleavable. Multifunctional oxime and hydrazone DG^auto were designed for C–H activation and alkyne annulation to furnish diverse nitrogen‐containing heterocycles. Imidazole was employed as an intrinsic DG (DGⁱⁿ) to synthesize ring‐fused and π‐extended functional molecules. The alkyne group in the substrates can also be served as DGⁱⁿ for ortho‐C–H activation to afford carbocycles. In this account, we intend to give a review of our progress in this area and brief introduction of other related advances on C–H functionalization using DG^auto or DGⁱⁿ strategies.