象形分子在有机化学及有机合成化学教学中的应用

激发学生学习兴趣,是提高课堂教学效果的关键。从化学科普网站收集象形分子,并用于有机化学及有机合成化学的课堂教学。通过象形分子形象逼真、妙趣横生、幽默及具艺术魅力的特点,调动学生学习的积极性和主动性,激发学习兴趣和热情,进而提高课堂趣味性,使教学内容形象生动。提高了教与学的效率和水平。     

基于FIAS的化学课堂师生言语行为个案研究

教师和学生的言语互动是教学活动最主要的方式,从某种意义上说,把握了课堂教学中师生言语行为也就把握了课堂教学的实质。本文以弗兰德斯互动分析系统（Flanders Interaction Analysis System,简称FIAS）为工具,对一节化学课的师生言语互动行为从课堂情感气氛、课堂结构、教师风格和提问的创新程度4个方面进行了定量分析,为课堂教学行为的实证研究提供了一种方法。     

物理化学教学改革探索:整合课堂内外教学

通过具体教学实例,阐述了如何通过整合课堂内外教学过程来显著提高物理化学课程的教学效果。这些实例包括:(1)选编预习作业和英文阅读材料;(2)在辅导课上对一道高考化学试题从物理化学角度进行深入分析;(3)根据化学史和物理化学主要内容安排课程论文。教学实践表明认真编写预习材料能够提高课堂教学效率;精心准备辅导内容能够巩固课堂教学成果;合理安排课程论文能够拓展课堂教学容量。     

化学演示实验课堂非言语性教学技能评价问卷初步编制

通过文献分析,开放式问卷调查和个别访谈,编制了化学演示实验课堂中非言语性教学技能的评价问卷。特殊性探索因素分析中的分层面个别因素分析将非言语性教学技能限定为板书技能、信息技术运用技能、教态变化技能、课堂管理组织技能、解题技能、课堂观察技能、演示实验技能等7个维度;验证性因素分析支持非言语性教学技能评价问卷结构;所编问卷具有较好的信度和效度,可以作为化学教师非言语性教学技能的有效测量工具。     

翻转课堂及其对高师院校化学教学论教学改革的启示

阐述了翻转课堂的含义、发展、特点、模式和国内外教学实验案例;从教学内容、教学结构、师生角色、评价方式和技术平台方面探讨了翻转课堂下化学教学论教学改革的思路;以"说课"为例进行教学设计,分析了翻转课堂下化学教学论的具体实施。     

大学生化学课堂笔记行为特点的研究*

研究从笔记内容、笔记位置、笔记格式、笔记详细程度和笔记编码程度等5个方面描述大学生的化学课堂笔记行为,分析了大学生化学课堂笔记行为的特点,比较了不同学业水平大学生的化学课堂笔记行为差异,为改进大学生化学课堂笔记行为提出相应的教学建议。     

在有机化学实验中设置计算化学模块

计算化学快速发展,对于化学研究有非常强的指导作用,因此将其引入本科低年级实验教学很有必要。本文在调研国内外高校计算化学课程开设情况的基础上,根据本院学生特点和课程的需要,在面向大一本科生的核心实验课程——有机化学实验中引入了计算模块。模块设计从实验问题出发,将计算项目和实验紧密结合,采用分层次教学的模式进行。利用Canvas线上教学平台对微课、讲义、作业、测验等学习资源进行有效组织,通过直播课和微信群进行讨论和答疑,以翻转课堂的形式进行混合式教学,取得了很好的教学效果。     

化学专业学生线上学习平台和学习效果评价研究*

从学生视角简要介绍了钉钉、腾讯会议、腾讯课堂、中国大学MOOC、QQ群等多个在线学习平台的特点和使用方法。基于2020年第一学期高校开展线上教学的实践,通过对化学及相关专业本科生进行问卷调查,发现由于缺少纸质教材、师生互动不便、网络平稳性差、学生听课时自控力不好等原因,学生对居家线上课堂听讲情况、学习态度等的自我满意程度较在校学习时差,一定程度上影响了学生线上专业学习的效果。基于调查结果,从专业教师和学生2个方面就提升线上教学效果提出了建议。     

新手熟手初中化学教师课堂教学行为特征的比较研究*——以“酸和碱”单元教学为例

通过对新手化学教师和熟手化学教师各4节“酸和碱”单元常态课堂中教师使用教学行为链、教学行为对在时间和频次等方面的特征进行对比分析发现,在教学行为链上,新、熟手化学教师都会在较高水平的教学行为链上花费更多的时间,熟手化学教师高水平教学行为链在频次上的占比要优于新手化学教师,在不同教学行为链时间安排上的合理性要更高一些;在教学行为对上,新、熟手化学教师都多以“问”和“讲”,学生多以“答”的方式来展开课堂活动,熟手化学教师在每一次“动”和“思”上所用时间要明显高于新手化学教师,学生参与课堂的水平上,熟手化学教师要优于新手化学教师。得出如下启示:与熟手化学教师相比,新手化学教师应有效地组织和安排课堂教学行为,注重对“酸和碱”学科内容本身及其教学的驾驭。无论是熟手还是新手化学教师均应进一步给予学生课堂参与的机会。     

实例引导与实践促动相结合普通化学教学探讨

在强调化学学科特点和重要性的基础上,通过实例引导型教学与促动学生实践性学习相结合的方式对大学普通化学教学新模式进行了探讨。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.