echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Wang Tao research group of Shaanxi Normal University: series reaction of isoquinoline nitrogen oxide and alkyne ketone compound without metal and additives

    Wang Tao research group of Shaanxi Normal University: series reaction of isoquinoline nitrogen oxide and alkyne ketone compound without metal and additives

    • Last Update: 2019-07-22
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com
    Quinoline and isoquinoline are important structural units of alkaloids and drug molecules As a member of the isoquinoline alkaloid family, N - fused polycyclic isoquinoline derivatives have a wide range of structural diversity and biological activities In addition to its remarkable biological activity, N - fused polycyclic isoquinoline derivatives also exhibit excellent luminescent properties, thus occupying an important position in materials science Therefore, the efficient "green" synthesis of N - fused isoquinoline is of great significance Recently, the research group of Wang Tao, associate professor of Shaanxi Normal University, has made a series of progress in this field (org Lett 2017, 19, 4327-4330; adv synth Catalyst 2019, 361, 696-701; org Lett 2019, DOI: 10.1021/acs.org lett 9b01966) Introduction to the research group of Associate Professor Wang Tao the research group was founded in 2015 At present, there are two masters and one undergraduate Four graduate students have graduated, one of whom has been supported by the "national construction of high-level university public graduate program" of the State Scholarship Committee to study for a doctorate in Spain, and two of whom have won the national scholarship for graduate students At present, the research group mainly focuses on two aspects: 1) homogeneous gold catalyzed chemical conversion, mainly developing a series of intermediate groups based on gold carbene 1, 2-transfer rearrangement reaction and transformation of diazo compounds mediated by gold carbene intermediate; 2) green synthesis methodology research, mainly developing green derivatization of pyridine, quinoline and isoquinoline, and testing the biological activity of the products Introduction to associate professor Wang Tao, associate professor In 2007 and 2011, he obtained bachelor's and master's degrees from Zhengzhou University and East China Normal University respectively; in September 2014, he obtained doctor's degree from Heidelberg University; in November 2014, he joined the school of chemistry and chemical engineering of Shaanxi Normal University The main research direction is organic synthesis methodology and functional organic molecule synthesis At present, he has presided over projects such as youth fund of National Natural Science Foundation of China, natural science fund of Shaanxi Province and Central University Fund In 2018, he was selected as one of the first batch of top young talents in "special support plan for high level talents" of Shaanxi Province Leading scientific research achievements: the series reaction of isoquinoline nitrogen oxide and alkyne ketone compounds (isoquinoline nitrogen oxide and alkyne derivatives) in the condition of no metal or additive, under different conditions, various chemical transformations can occur, and a variety of (isoquinoline derivatives) can be obtained regionally selectively (scheme 1) For example, under the catalysis of transition metal RH and co complex, 8-Position functionalized quinoline derivatives can be obtained; under the promotion of microwave, 3-position (meta -) functionalized quinoline derivatives can be obtained Recently, Wang Tao, associate professor of Shaanxi Normal University and Ji Kegang, Professor of northwest agricultural and Forestry University respectively found that 2-position (ortho -) functional quinoline derivatives can be obtained by the reaction of quinoline nitrogen oxides with alkynone compounds without metal or additives By using this reaction, Wang Tao's research group realized the efficient synthesis of a series of (isoquinoline) derivatives (org Lett 2017, 19, 4327-4330; adv synth Catalyst 2019, 361, 696-701) Based on the previous work, this paper reported the efficient synthesis of benzodiazepine [2,1-a] isoquinoline derivatives without metal and additives (org Lett 2019, DOI: 10.1021/acs.orglett 9b01966) (source: org Lett.) the author tried to use alkynone 1a and isoquinoline nitrogen oxide 2A as template substrate for the reaction (Table 1) In consideration of the formation of equivalent HCl in the reaction process, the author first added equivalent DABCO as an acid binding agent and carried out the reaction in acetonitrile at 60 ℃, resulting in the target compound 3a with 69% separation yield When K 2CO 3 was used instead of DABCO, the yield of 3A was increased to 85% Surprisingly, the subsequent optimization of conditions showed that the reaction could be carried out without adding alkali Through further optimization of the reaction conditions, the author finally determined the optimal reaction conditions: acetone as solvent, reaction at 80 ℃ for 24 hours (source: org Lett.) after obtaining the optimal conditions, the author investigated the universality of the reaction (scheme 2) When R 1 is substituted phenyl, heteroaryl and alkyl, the reaction can proceed smoothly, and the corresponding target product (3a - 3l, 62% - 98%) can be obtained in high yield For alkyne ketone substrate, the author investigated the substrate with R 2 group as halogen atom and electron donor group, and obtained the target product (3m - 3O, 75% - 95%) in high yield When isoquinoline nitrogen oxides with different substituents react with alkyne ketone 1a, the target product 3P - 3S is obtained in 82% - 98% yield Unfortunately, when 5-nitroisoquinoline-n-oxide, quinoline-n-oxide and Pyridine-N-oxide were placed in the standard reaction conditions, complex mixtures were obtained This is consistent with the results of the reaction activity observed in the author's previous work: isoquinoline nitrogen oxide > quinoline nitrogen oxide > pyridine nitrogen oxide (source: org Lett.) based on the above results and previous work, the author proposed the following possible mechanism (scheme 3) First, the intermediate I of isoxazole - [3,2-a] - isoquinoline was produced by [3 + 2] cycloaddition reaction between 1a and 2A Subsequently, the ring opening of isoxazole leads to the intermediate II, which can be tautomerized with II 'by imino enamine In order to confirm the rationality of ring opening of intermediate I to get II or II ', DFT calculation has been carried out The results show that the free energy of intermediate I is more than 50kcal / mol higher than that of intermediate II and II ' Therefore, it is not difficult to understand that I is prone to open-loop to obtain II or II ' Finally, the intermediate II or II 'can obtain the final product 3A through intramolecular nucleophilic substitution reaction (source: org Lett.) the author's previous study found that this kind of n-fused polycyclic isoquinoline derivatives often showed excellent fluorescence properties Subsequently, the fluorescence properties of benzoaza [2,1-a] isoquinoline derivative 3 were also studied Interestingly, the compound showed double emission at 414 nm and 438 nm respectively in chloroform solution, and the different substituents had no effect on the emission wavelength (Figure 2) (source: org Lett.) conclusion: the author developed a rapid and efficient method for the preparation of benzodiazepine [2,1-a] isoquinoline This method is a "green" synthesis method with simple operation, mild reaction conditions and no need of catalyst and additives This achievement was recently published on organic letters (DOI: 10.1021 / ACS Orglett 9b01966) The authors include Li Xuetong, a master student, Du Xinru, an undergraduate student, Zhang Zunting, a professor of the school of chemistry and chemical engineering, Shaanxi Normal University, and Dr Zhou Guanghua, Nanchang Normal University The corresponding author is Associate Professor Wang Tao The above research work was supported by NSFC, NSFC of Shaanxi Province, basic scientific research fund of Central University and "special support program for high level talents" of Shaanxi Province Nowadays, people and scientific research have been paid more and more attention in the economic life China has ushered in the "node of science and technology explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeangoapp, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the column of "people and scientific research", approach the domestic representative research group, pay attention to their research, listen to their stories, record their demeanor, and explore their scientific research spirit.
    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.