We report here a Ni-NPs-catalyzed one-pot synthesis of 2-alkyl/aryl quinazolinone motifs via acceptorless dehydrogenation of alcohol, condensation of an aldehyde intermediate with 2-aminobenzamide, followed by a second dehydrogenation of the cyclized intermediate. The protocol is atom-economical and require earth-abundant Ni as the catalyst. The present report involves the annulation of 2-aminobenzamide with various types of primary alcohols, including aryl/heteroaryl methanol, and aliphatic alcohols, and produces high yields of the desired products under neat conditions. The catalyst was synthesized via a high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template. The Ni NPs@N-C catalyst was characterized by XPS, HR-TEM, HAADF-STEM, XRD, and ICP-MS. The catalyst is stable even in air at room temperature and displayed excellent activity in the acceptorless dehydrogenative coupling synthesis of quinazolinones and could be recycled five times without appreciable loss of its activity.
我们在此报告了一种 Ni-NPs 催化的单锅合成 2-烷基/芳基喹唑啉酮基团的方法,该方法通过醇的无受体脱氢、醛中间体与 2- 氨基苯甲酰胺的缩合,然后对环化中间体进行第二次脱氢。该方案原子经济,需要地球上丰富的 Ni 作为催化剂。本报告涉及 2-氨基苯甲酰胺与各种类型的伯醇(包括芳基/杂芳基甲醇和脂肪醇)的环化反应,并在纯净条件下产生高产率的所需产物。该催化剂是以 ZIF-8 为牺牲模板,通过高温热解策略合成的。通过 XPS、HR-TEM、HAADF-STEM、XRD 和 ICP-MS 对 Ni NPs@N-C 催化剂进行了表征。该催化剂即使在室温空气中也很稳定,在喹唑啉酮类化合物的无受体脱氢偶联合成中表现出优异的活性,并且可以循环使用五次而不会明显降低其活性。
{"title":"Acceptorless Dehydrogenation under Neat Reaction Conditions: Synthesis of 2-Aryl/Alkyl Quinazolinones Using Supported Ni NPs as Catalyst","authors":"Vageesh MM, Omkar Patil, Hima PP, Raju Dey","doi":"10.1055/a-2388-9487","DOIUrl":"https://doi.org/10.1055/a-2388-9487","url":null,"abstract":"<p>We report here a Ni-NPs-catalyzed one-pot synthesis of 2-alkyl/aryl quinazolinone motifs <i>via</i> acceptorless dehydrogenation of alcohol, condensation of an aldehyde intermediate with 2-aminobenzamide, followed by a second dehydrogenation of the cyclized intermediate. The protocol is atom-economical and require earth-abundant Ni as the catalyst. The present report involves the annulation of 2-aminobenzamide with various types of primary alcohols, including aryl/heteroaryl methanol, and aliphatic alcohols, and produces high yields of the desired products under neat conditions. The catalyst was synthesized <i>via</i> a high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template. The Ni NPs@N-C catalyst was characterized by XPS, HR-TEM, HAADF-STEM, XRD, and ICP-MS. The catalyst is stable even in air at room temperature and displayed excellent activity in the acceptorless dehydrogenative coupling synthesis of quinazolinones and could be recycled five times without appreciable loss of its activity.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"29 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For hundreds of years, it seems that people have needed stirring to conduct chemical experiments. This operation can be seen everywhere in chemical, pharmaceutical, and materials laboratories and factories. People generally believe that stirring helps with processes such as material dispersion, dissolution, and collision, thereby enabling more-efficient reactions. However, why do chemical reactions that occur in Nature not require stirring? What are the facts? For this purpose, we investigated a total of 329 organic chemical reactions in eight categories and 25 types, including 26 chemical reactions magnified to gram or even kilogram levels. Under the same conditions of temperature, humidity, pressure, and reaction time, we compared the reaction yields under stirring and standing conditions. More than 600 results showed that stirring or not stirring had almost no effect on the efficiency of chemical reactions in solution. If most chemists performing reactions turned off the agitator, it would not be difficult to imagine how much electricity could be saved!
{"title":"Comparison of the Effects of Stirring and Standing on Chemical Reactions","authors":"Xianting Huang, Jianyou Zhao, Qingxu Wang, Pengkai Fang, Wei Xie, Meng Chen, Hongliang Han, Lanlan Zhang, Jiatai Zhang, Fan Wang, Zhong-Quan Liu","doi":"10.1055/a-2384-7220","DOIUrl":"https://doi.org/10.1055/a-2384-7220","url":null,"abstract":"<p>For hundreds of years, it seems that people have needed stirring to conduct chemical experiments. This operation can be seen everywhere in chemical, pharmaceutical, and materials laboratories and factories. People generally believe that stirring helps with processes such as material dispersion, dissolution, and collision, thereby enabling more-efficient reactions. However, why do chemical reactions that occur in Nature not require stirring? What are the facts? For this purpose, we investigated a total of 329 organic chemical reactions in eight categories and 25 types, including 26 chemical reactions magnified to gram or even kilogram levels. Under the same conditions of temperature, humidity, pressure, and reaction time, we compared the reaction yields under stirring and standing conditions. More than 600 results showed that stirring or not stirring had almost no effect on the efficiency of chemical reactions in solution. If most chemists performing reactions turned off the agitator, it would not be difficult to imagine how much electricity could be saved!</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"41 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hetavi A. Vadariya, Gaurav Badhani, B. Mohamed Farves, Krupa N. Boda, Subbarayappa Adimurthy
N-Formylation of anilines using a renewable aleuritic acid as an eco-friendly and sustainable formylating source has been developed. para-Substituted anilines generally provided good yields, while moderate yields were observed with meta- and ortho-substituted derivatives. In situ generated formic acid through oxidative cleavage of aleuritic acid serve as a formyl source, which has been confirmed through control experiments.
{"title":"Sustainable N-Formylation of Anilines: Harnessing Aleuritic Acid as a Renewable Formyl Source","authors":"Hetavi A. Vadariya, Gaurav Badhani, B. Mohamed Farves, Krupa N. Boda, Subbarayappa Adimurthy","doi":"10.1055/a-2388-9578","DOIUrl":"https://doi.org/10.1055/a-2388-9578","url":null,"abstract":"<p>\u0000<i>N</i>-Formylation of anilines using a renewable aleuritic acid as an eco-friendly and sustainable formylating source has been developed. <i>para</i>-Substituted anilines generally provided good yields, while moderate yields were observed with <i>meta</i>- and <i>ortho</i>-substituted derivatives. <i>In situ</i> generated formic acid through oxidative cleavage of aleuritic acid serve as a formyl source, which has been confirmed through control experiments.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"195 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new method for the O-methylation of cinnamic acid employing DMSO as the methylating agent has been devised, employing a Ni-DMAP complex as catalyst along with Ag2O and dimethylamine as additives. This protocol demonstrates broad substrate compatibility and good tolerance towards various functional groups. The key advantages of this approach include the utilization of cost-effective catalysts, moderate to high yield of the products, and short reaction time.
{"title":"Nickel-Catalyzed O-Methylation of Cinnamic Acid Using DMSO as Methyl Surrogate","authors":"Hrishikesh Talukdar, Prodeep Phukan","doi":"10.1055/a-2384-6807","DOIUrl":"https://doi.org/10.1055/a-2384-6807","url":null,"abstract":"<p>A new method for the <i>O</i>-methylation of cinnamic acid employing DMSO as the methylating agent has been devised, employing a Ni-DMAP complex as catalyst along with Ag<sub>2</sub>O and dimethylamine as additives. This protocol demonstrates broad substrate compatibility and good tolerance towards various functional groups. The key advantages of this approach include the utilization of cost-effective catalysts, moderate to high yield of the products, and short reaction time.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"26 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dwaipayan Das, Rahul Dev Mandal, Prasun Mukherjee, Pranabes Bhattacharya, Asish R. Das
The impetuous development of the pharmaceutical industry and material science stimulates the search for new synthetic approaches and new methods for the synthesis and functionalization of aza-heterocycles; these are some of the key objectives of modern organic chemistry. As a result, an advanced method towards the synthesis of functionalized N-heterocycles that circumvents the limitations associated with traditional methods needs to be devised. In recent decades, rearrangement/reorganization reactions have emerged as a powerful tool for the efficient synthesis of the aza-heterocycle. In this illustration, we summarize some our recent efforts in the development of few complex aza-heterocyclic cores.
1 Introduction
2 Skeletal Rearrangement of Small Heterocycles via Domino Ring-Opening and Ring-Closing (DROC) Strategy
3 Ru(II)-Catalyzed Skeletal Rearrangement of the Quinazoline Ring
4 Lewis Acid Catalyzed Skeletal Rearrangement of Furans to Indolizine Cores
5 Skeletal Rearrangement of Donor–Acceptor Cyclopropanes via Domino Ring-Opening and Ring-Closing (DROC) Strategy
6 Lewis Acid Mediated Skeletal Rearrangement of Donor–Acceptor Spirocyclopropylpyrazolones
7 Skeletal Rearrangement through Ring Distortion Strategy
8 Conclusion
制药业和材料科学的迅猛发展刺激着人们寻找新的合成方法和新的氮杂环合成及功能化方法;这些是现代有机化学的一些关键目标。因此,需要设计一种先进的方法来合成功能化的 N-杂环,以规避传统方法的局限性。近几十年来,重排/重组反应已成为高效合成氮杂环的有力工具。在本说明中,我们总结了最近在开发少数复杂氮杂环核心方面所做的一些努力。1 引言 2 通过多米诺开环和闭环(DROC)策略实现小杂环的骨架重排 3 Ru(II)-Catalyzed Skeletal Rearrangement of the Quinazoline Ring 4 Lewis Acid Catalyzed Skeletal Rearrangement of Furans to Indolizine Cores 5 通过多米诺开环和闭环(DROC)策略实现供体-受体环丙烷的骨架重排。路易斯酸介导的供体-受体螺环丙基吡唑酮的骨架重排 7 通过环畸变策略实现的骨架重排 8 结论
{"title":"Skeletal Reorganization: Approaches towards the Synthesis of Aza-Heterocyclic Cores","authors":"Dwaipayan Das, Rahul Dev Mandal, Prasun Mukherjee, Pranabes Bhattacharya, Asish R. Das","doi":"10.1055/a-2384-6583","DOIUrl":"https://doi.org/10.1055/a-2384-6583","url":null,"abstract":"<p>The impetuous development of the pharmaceutical industry and material science stimulates the search for new synthetic approaches and new methods for the synthesis and functionalization of aza-heterocycles; these are some of the key objectives of modern organic chemistry. As a result, an advanced method towards the synthesis of functionalized N-heterocycles that circumvents the limitations associated with traditional methods needs to be devised. In recent decades, rearrangement/reorganization reactions have emerged as a powerful tool for the efficient synthesis of the aza-heterocycle. In this illustration, we summarize some our recent efforts in the development of few complex aza-heterocyclic cores.</p> <p>1 Introduction</p> <p>2 Skeletal Rearrangement of Small Heterocycles via Domino Ring-Opening and Ring-Closing (DROC) Strategy</p> <p>3 Ru(II)-Catalyzed Skeletal Rearrangement of the Quinazoline Ring</p> <p>4 Lewis Acid Catalyzed Skeletal Rearrangement of Furans to Indolizine Cores</p> <p>5 Skeletal Rearrangement of Donor–Acceptor Cyclopropanes via Domino Ring-Opening and Ring-Closing (DROC) Strategy</p> <p>6 Lewis Acid Mediated Skeletal Rearrangement of Donor–Acceptor Spirocyclopropylpyrazolones</p> <p>7 Skeletal Rearrangement through Ring Distortion Strategy</p> <p>8 Conclusion</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"58 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The synthesis of short phosphorodiamidate morpholino oligonucleotides (PMOs) has been successfully achieved using azidoaryl carbamate protected chlorophosphoramidate monomers. The deprotection step carried out in a neutral medium with triphenylphosphine-based reagents avoids the need for chlorinated solvents. This method uses a meticulously tailored combination of resin support, solvents, deblocking agents, and coupling reagents to ensure efficient synthesis. Additionally, the azidoaryl carbamate protecting group has been adapted as an orthogonal protection, enabling the development of bi- and trifunctionalized PMOs for bioconjugation. These advancements are expected to broaden the potential applications of PMOs in biomedical research.
{"title":"Synthesis of Phosphorodiamidate Morpholino Oligonucleotides (PMOs) Using Staudinger Reduction as a Deblocking Condition and Its Usefulness for Orthogonal Conjugation in Bi- and Trifunctionalized PMOs","authors":"Subhamoy Pratihar, Md Qasim, Surajit Sinha","doi":"10.1055/a-2384-7323","DOIUrl":"https://doi.org/10.1055/a-2384-7323","url":null,"abstract":"<p>The synthesis of short phosphorodiamidate morpholino oligonucleotides (PMOs) has been successfully achieved using azidoaryl carbamate protected chlorophosphoramidate monomers. The deprotection step carried out in a neutral medium with triphenylphosphine-based reagents avoids the need for chlorinated solvents. This method uses a meticulously tailored combination of resin support, solvents, deblocking agents, and coupling reagents to ensure efficient synthesis. Additionally, the azidoaryl carbamate protecting group has been adapted as an orthogonal protection, enabling the development of bi- and trifunctionalized PMOs for bioconjugation. These advancements are expected to broaden the potential applications of PMOs in biomedical research.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"9 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report a useful synthetic approach to assemble in/in epoxide, in/out epoxide, and out/out epoxide in cage systems using the Corey–Chaykovsky reaction and the Peterson olefination as key steps. In this regard, a variety of pentacycloundecane (PCUD) based cage compounds containing oxirane rings with diverse stereochemical disposition were synthesized via a simple synthetic sequence. Five cage diones were used for this purpose, and the starting cage diones were prepared with easily accessible starting materials such as 1,4-hydroquinone derivatives and cyclopentadiene. Here, we have used the Diels–Alder (DA) reaction, a [2+2] photocycloaddition, the Corey–Chaykovsky reaction, and the Peterson olefination as crucial steps to prepare the target molecules.
{"title":"Design and Synthesis of Out/Out, Out/In, and In/In Epoxides in Polycyclic Cage Frameworks","authors":"Sambasivarao Kotha, Mohammad Salman","doi":"10.1055/a-2384-6736","DOIUrl":"https://doi.org/10.1055/a-2384-6736","url":null,"abstract":"<p>We report a useful synthetic approach to assemble in/in epoxide, in/out epoxide, and out/out epoxide in cage systems using the Corey–Chaykovsky reaction and the Peterson olefination as key steps. In this regard, a variety of pentacycloundecane (PCUD) based cage compounds containing oxirane rings with diverse stereochemical disposition were synthesized <i>via</i> a simple synthetic sequence. Five cage diones were used for this purpose, and the starting cage diones were prepared with easily accessible starting materials such as 1,4-hydroquinone derivatives and cyclopentadiene. Here, we have used the Diels–Alder (DA) reaction, a [2+2] photocycloaddition, the Corey–Chaykovsky reaction, and the Peterson olefination as crucial steps to prepare the target molecules.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"7 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A sequential Cu-catalyzed amidation and hydroxylation of p-dihalobenzenes is applied to synthesize acetaminophen. This method allows the direct introduction of acetamido and hydroxy groups under acid-free conditions without forming other regioisomers. By using a one-pot process, acetaminophen can be prepared with an overall yield of up to 74%.
{"title":"Sequential Copper-Catalyzed Amidation and Hydroxylation for Acetaminophen Synthesis","authors":"Youngran Seo, Dongwon Yoo, Young Gyu Kim","doi":"10.1055/a-2384-7081","DOIUrl":"https://doi.org/10.1055/a-2384-7081","url":null,"abstract":"<p>A sequential Cu-catalyzed amidation and hydroxylation of <i>p</i>-dihalobenzenes is applied to synthesize acetaminophen. This method allows the direct introduction of acetamido and hydroxy groups under acid-free conditions without forming other regioisomers. By using a one-pot process, acetaminophen can be prepared with an overall yield of up to 74%.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"24 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review summarizes various strategies that combine metathesis with diverse named and unnamed reactions to create molecular diversity in producing carbocycles, macrocycles, and heterocycles.
{"title":"Design of Molecular Diversity by Olefin Metathesis in Tandem with Other Reactions","authors":"Sambasivarao Kotha, Naveen Kumar Gupta, Saima Ansari, Deepshikha Singh","doi":"10.1055/a-2379-9912","DOIUrl":"https://doi.org/10.1055/a-2379-9912","url":null,"abstract":"<p>This review summarizes various strategies that combine metathesis with diverse named and unnamed reactions to create molecular diversity in producing carbocycles, macrocycles, and heterocycles.</p> <p>1\tIntroduction</p> <p>2 Olefinations</p> <p>3 Rearrangement</p> <p>4 Allylation</p> <p>5 Cycloadditions</p> <p>6 Coupling Reactions</p> <p>7 Grignard Reaction</p> <p>8 Radical reactions</p> <p>9 Conjugate Addition–Metathesis</p> <p>10 Multicomponent Reactions</p> <p>11 Miscellaneous</p> <p>12 Conclusions</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"112 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Here, we report the NiCo2O4-nanoparticle-catalyzed dehydrogenative direct oxidation of primary alcohols to carboxylic acid in the presence of KOH under microwave irradiation in the absence of any oxidant in good to excellent yields (75–99%) within a short reaction time (5–10 min). The polycrystalline cubic spinel phase of NiCo2O4 nanoparticles (NPs) with an average size of 25 nm were synthesized by the co-precipitation method and analyzed properly by using powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy measurements. The NiCo2O4 NPs were stable under the reaction conditions and reused for up to eight cycles without appreciable loss in the yield of benzoic acid. According to mechanistic insight, the KOH acts as a second oxygen source and is essential for the synthesis of carboxylic acid from alcohols. The hydrogen gas was found to be the only byproduct of this method detected by chemical reactions.
在此,我们报告了在微波辐照下,在没有任何氧化剂的情况下,NiCo2O4 纳米粒子催化伯醇直接氧化成羧酸的脱氢反应,在很短的反应时间(5-10 分钟)内就获得了良好到极佳的产率(75-99%)。共沉淀法合成了平均粒径为 25 nm 的多晶立方尖晶石相 NiCo2O4 纳米粒子(NPs),并通过粉末 X 射线衍射、场发射扫描电子显微镜、能量色散 X 射线光谱和透射电子显微镜测量进行了正确分析。NiCo2O4 NPs 在反应条件下非常稳定,可重复使用八次,苯甲酸的产率没有明显下降。根据机理分析,KOH 可作为第二氧气源,是醇类合成羧酸的关键。氢气是该方法通过化学反应检测到的唯一副产品。
{"title":"NiCo2O4-Nanoparticle-Catalyzed Microwave-Assisted Dehydrogenative Direct Oxidation of Primary Alcohols to Carboxylic Acids under Oxidant-Free Conditions","authors":"Kumari Anchal, Ashok R. Patel, Subhash Banerjee","doi":"10.1055/a-2384-6371","DOIUrl":"https://doi.org/10.1055/a-2384-6371","url":null,"abstract":"<p>Here, we report the NiCo<sub>2</sub>O<sub>4</sub>-nanoparticle-catalyzed dehydrogenative direct oxidation of primary alcohols to carboxylic acid in the presence of KOH under microwave irradiation in the absence of any oxidant in good to excellent yields (75–99%) within a short reaction time (5–10 min). The polycrystalline cubic spinel phase of NiCo<sub>2</sub>O<sub>4</sub> nanoparticles (NPs) with an average size of 25 nm were synthesized by the co-precipitation method and analyzed properly by using powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy measurements. The NiCo<sub>2</sub>O<sub>4</sub> NPs were stable under the reaction conditions and reused for up to eight cycles without appreciable loss in the yield of benzoic acid. According to mechanistic insight, the KOH acts as a second oxygen source and is essential for the synthesis of carboxylic acid from alcohols. The hydrogen gas was found to be the only byproduct of this method detected by chemical reactions.</p> ","PeriodicalId":22319,"journal":{"name":"Synlett","volume":"8 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}