Palladium-catalyzed Buchwald-Hartwig coupling reaction is a very direct and efficient method for the formation of C—N bonds. The N-heterocyclic carbene-palladium complexes have the advantages of stable performance and high catalytic activity, and are high-efficient catalysts for the Buchwald-Hartwig coupling reactions. This article aimed to briefly introduce the research progress in this field during the past three years.

Material chemistry is an emerging interdisciplinary subject, and its teaching content has not been unanimously recognized. Focusing on the goal of cultivating talents in material chemistry specialty, some explorations have been made on the teaching reform of the material chemistry course, such as selecting appropriate textbook and teaching contents, promoting the modernization and diversity of teaching methods, cultivating students' practical ability, reforming and innovating assessment methods, and so on.

Taking the discussion and research of new methods for determining the end point of potentiometric titration as an example, this paper introduces the exploration of integrating the cultivation of innovative ability into the teaching of basic courses from five aspects. Through this study, students' enthusiasm for basic courses and learning quality have been improved. Firstly, we improved the method of calculating the end point of D-value second derivative. The tada tables of D-value second derivative, Δ²E/ΔV-V, were calculated by Excel, then calculating the linear equation of the highest and lowest points in tata table by Excel, y=ax+b,let y=0, x=-b/a is the end point. Secondly, we have developed a new method to determine the end point of potentiometric titration by derivative the simulated titration curve. The titration curve was simulated by the cubic equation with Excel, y=ax³+bx²+cx+d, the second derivation is d²y/dx²=6ax+2b, let d²y/dx²=0, x=-b/3a is the end point. 2

An important fascination of physical chemistry is that some formulas are cross-correlated. Taking the adiabatic process equation of ideal gas as an example, this paper describes in detail the deduction process from the four different starting points including the first law of thermodynamics, the formulas for calculating the entropy difference, the partial differential relations and the total differential equations, by using the necessary thermodynamic relations, and finally reaching the same end point.

In this paper, based on a novel and high-efficiency gas generator, an experimental scheme was designed to convert potassium manganate into potassium permanganate in a 100% theoretical yield using chlorine as oxidant. The experimental results show that a high purity potassium permanganate can be obtained using this scheme. It can not only guarantee the theoretical conversion rate of potassium permanganate, but also reduce the influence of the by-products on the purity of product using disproportionation reaction. At the same time, the by-products, sodium hypochlorite and chlorine water, can be used as basic reagents in inorganic teaching experiments well followed the guidance of “circular economy”.

Concentrated sulfuric acid usually used as catalyst in the experimental teaching of ethyl acetate preparation, but which has many shortcomings, such as unsafe, too much secondary reaction, serious corrosion, complicated final treatment and so on. In view of these shortcomings, the solid acid formed by concentrated sulfuric acid loaded on silica gel was designed as catalyst, and its application in experimental teaching of ethyl acetate was explored, including teaching content, organization form, evaluation methods, etc. The method has some advantages, for example simple operation, safety, high yield and recyclability of catalyst, which conforms to the concept of green chemistry, and fully embodies the supporting function of scientific research on teaching.

This paper proposed a multi-dimensional teaching mode with online self-study, offline teaching and experimental training in lab for inorganic and analytical chemistry experiment teaching, in which wechat public platform as the carrier, clinical cases as the heuristic point and problems as orientation. According to learning interest, ability training and teaching effectiveness, an evaluation was made between four teaching-reform classes and other four control classes reflected by final examination, teaching quality evaluation and questionnaire. The results showed that the average score of the students in the four teaching-reform classes were 12.6 higher than that of the control classes. Practice showed that the multi-dimensional teaching mode was helpful to solve the problems of less hours of experiment and limited availability of labs. Moreover, the novel teaching method stimulated the students' learning interests, innovative thinking ability as well as improved their scientific research quality. It provides an effective way for training innovation talents.

The cyclic diphenyl iodide salt was synthesized from 2-iodoaniline and phenylboronic acid by Suzuki coupling reaction, diazotization reaction and oxidation reaction, and further applied to the synthesis of dibenzothiophene. This experiment involves the synthesis, structural characterization and application of organic compounds. Combining the basic theoretical knowledge of organic chemistry, basic experimental skills and research hotspots in organic chemistry can effectively cultivate students' scientific research literacy. The experiment involves the use of gas chromatography-mass spectrometry, nuclear magnetic resonance spectrometry and melting point instruments. It enhances the ability of students to operate the instruments and comprehensive experimental skills, and is suitable for comprehensive experiments of senior students.

The synthesis of N-(1-cyclohexenyl)morpholine in textbook is to use morpholine and cyclohexanone condensation reaction, p-toluene sulfonic acid as catalyst and toluene as water-carrying agent. There are some disadvantages of this method including long reaction time, high toluene content of toxic gas in laboratory, deep color of the product and low yield(<60%). Based on the same experimental purpose, principle and content, we propose some new operations as following to improve the experimental results: using morpholine and cyclohexanone (1.6 in mol ratio), pre-condensation reaction of 1 h before adding water carrying agent, adding hydroquinone into system,using cyclohexane as water carrying agent and fractionating to purify the product. The improved experiment shows that the reaction time is shortened by 1 h, the indoor air environment is friendly, the product is almost colorless, and the yield could reach more than 80%.

In this paper, a teaching experiment of inorganic chemistry was designed, which included two parts: (1) synthesis of catalyst precursor Ni[P(OEt)₃]₄; (2) synthesis of catalyst HNiL⁺₃ [L=P(OEt)₃] in situ and isomerization of 2-propenyl benzene under anhydrous and inert atmosphere. In this experiment, the results of alkene isomerization were detected by high performance liquid chromatography and the possible mechanism of isomerization was given. Based on the experimental data of the students, the factors affecting the yield of the catalyst precursors and the conversion rate of alkene isomerization were analyzed in depth. The ability of the students in Schlenk technique, low temperature reaction, control of micro-reaction and the principle and usage of high performance liquid chromatography was trained and improved.

The chemistry teaching design scale (CTDES) was used to evaluate the teaching design of 86 chemistry normal students in a university in Guangzhou during the educational internship. It was found that the students performed moderately in “cognition and metacognition”, “social culture and emotion”, “scientific description and application” indicators and performed well in the “consistency” indicator. In the teaching design of the “theoretical chemistry” and “description chemistry” subjects, the chemistry normal students have significant differences in the scores on the three indicators of “cognition and metacognition”, “social culture and emotion”, and “scientific description and application”.

This study aimed to explore the influencing factors of pre-service chemistry teachers integrating nature of science instruction into regular chemistry teaching. Multiple qualitative data sources included participants' lesson plans, classroom video, reflection papers, group discussion recording and focus group interview. The inductive and constant comparative method used to analyze data. Results showed that factors that hindered pre-service chemistry teachers from teaching the nature of science included the teacher's knowledge structure, prior learning experience and limited teaching materials; personal motivation and expectations, team support, ongoing participation and reflection played a positive role in promoting.

This paper outlines the application of problem-oriented teaching mode in the chapter on buffer solution and its mechanism in the course of Medical Basic Chemistry in medical colleges.Teachersconduct theoretical teaching of buffer solution and its mechanism through layer-by-layer questions, sequential method of teaching. It can effectively improve students' interests in learning, and enable students to master the basic theory and core concepts of buffer solution and its mechanism in a limited number of hours, and develop students' 4C ability.

An open experiment in environmental chemistry was introduced. In this experiment, dilute HCl, EDTA and CaCl₂ were used as leaching reagents to remediate soils contaminated by heavy metals. Soil Pb and Cd contents was analyzed by inductively coupled plasma atomic emission spectroscopy before and after the leaching procedure. This experiment can help students to deepen their understanding of the knowledge of environmental chemistry including complexation/chelation, acid-base reaction, ion exchange reaction, properties of colloids, heavy metal speciation in soil, soil properties and composition. Students choose their own soil sample and the physi-chemical properties of different types of soils influence the efficiency of leaching, thus the uncertainty of the experiment can be increased. This experiment shows the frontier of the subject and is associated with real engineering practice, which encourages students to think and explore independently. Their ability of research and solving complicated problems can be enhanced.

Using existing laboratory equipment and combined with theoretical knowledge andscientific research achievements of the teacher, an innovative experiment was designed, mainly using oxygen as an oxygen source, using organometallic salt as a catalyst, and metal oxides as auxiliaries, at a certain temperature and pressure. The epoxidation reaction between soybean oil and oxygen was carried out, and then vacuum distillation was carried out to obtain a purer epoxy soybean oil. The measured epoxide value of the product was higher. The effects of oxygen content, reaction temperature, reaction time and reaction pressure on the epoxide value of the product were investigated. Through the experimental process, students' innovative ability and scientific research interest are cultivated.

In this study, the application of micro-kinetic simulation software MKMCXX in the teaching of chemical kinetics was discussed by means of Rh-catalyzed Fischer-Tropsch synthesis. Based on the energy barriers and reaction energy calculated by density functional theory (DFT), the micro-kinetic model was constructed by MKMCXX software to calculate the intermediate species surface coverage, reaction rate, reaction order and apparent activation energy, which provide students a better understanding of chemical kinetic.

With 43 pre-service chemistry teachers from a normal university in Guangdong as participants, this study employed open-ended questionnaire and interviews to investigate their perception of change and its teaching. The results indicated that pre-service chemistry teachers generally lacked understanding about change(especially philosophical perspective) and its teaching (including knowledge of curriculum and strategies for concept-base teaching). Relevant suggestions for pre-service chemistry teacher education were also provided

When phosphoric acid and sodium hydroxide are mixed, the composition of the solution is more intricate, and the calculation of hydrogen ion concentration is more complicated. However, in the approximate calculation of pH, only the main components of the mixed solution are usually considered, and then the corresponding formula can be selected according to the main components. Therefore, the analysis of the main components of the mixed solution becomes the key to the calculation of hydrogen ion concentration of such solution. This paper firstly analyzed the main components of the solution of phosphoric acid and sodium hydroxide in different mole ratio, and then mainly discussed and derived relevant calculation formulas for mixing different buffer solutions. The formula has strong patterns, which is practical and easy for student to master and apply.

The chemical nonequivalence of proton hydrogen in prochiral groups of ¹H-NMR spectroscopy was categorized and summarized in detail. Some examples were provided to elaborate it. Our description will provide material supplement and reference for the systematic teaching of chemical nonequivalence content.

The hotspots of international pre-service chemistry teacher education research can be used as reference for the development of pre-service chemistry teacher education in China. It takes 47 papers on Chemical Education Research and Practice in pre-service chemistry education research as the research object, analyzes it by content analysis method and bibliometrics, and compares it with the domestic research status. We find that the literature output is not high both domestic and foreign, and the relevant foreign research results have only begun to flourish in the past five years, but there is a big gap in the distribution of authors, research topics, and research paradigms. Specific performance: Foreign scholars pay attention to cross-professional, inter-school, and cross-border cooperation in pre-service chemistry teacher education; they tend to conduct surveys or tests from the perspective of students, based on evidence for students' learning and even teachers' teaching reform strategies. Foreign scholars are good at empirical research, which are different with the summary of experience the domestic research paradigms.

The Enlightenment Textbook is the first complete set of teaching material for child in China, published by Shanghai Civilization Press in 1906, serving as the miletone for the birth of modern Chinese textbook. As one of the series, Enlightenment Chemistry Textbook represented the highest level of chemical enlightenment education at that time. By studying its background, content, arrangement, and significance, we can have a clear view of chemical enlightenment education in late Qing dynasty. It is of significance for the development of elementary chemistry education in China.