Progress in ruthenium catalyzed activation of long-range hydrocarbon bonds by Zhao Yingsheng, Suzhou University

Introduction: In recent years, there have been a lot of reports on the selective o-hydrocarbon bond activation of aromatic rings with Ru as catalyst In contrast, there are few reports on the selective o-hydrocarbon bond activation Among them, Ackermann group has previously reported that the first-order alkyl halide and the second-order alkyl halide can realize the O-alkylation and the m-alkylation respectively The regioselectivity is still affected by the reaction substrate, and it is still not completely controlled by Ru catalytic reaction system Recently, Zhao Yingsheng group of Suzhou University has made a great breakthrough in ruthenium catalyzed remote hydrocarbon bond activation Zhao Yingsheng, associate professor, Zhao Yingsheng, associate professor, School of chemistry, Suzhou University, master tutor Relevant research work was published in the international authoritative chemical academic journals such as org Chem Front.; angel Chem Int ed.; ACS catalyst Education and academic experience: 2012 to date, associate professor of Suzhou University, 2010-2012, postdoctoral of Prof Gong Chen research group, University of Pennsylvania, USA, 2008-2010, postdoctoral of Prof Ryoji Noyori research group, University of Nagoya, Japan, 2003-2008, Professor Lei Aiwen of Wuhan University, Dr Zhang Xumu research group, 1999-2003, Associate Professor Zhao Yingsheng, Bachelor of Southwest University At present, Zhao Yingsheng's research team mainly focuses on the conversion of hydrocarbon bond functional groups, activation of carbon oxygen bonds, activation of small molecules (CO, CO2, no, O2, etc.), and semi synthesis of natural products and bioactive molecules Expand the range of substrate for activation of hydrocarbon bond and promote the practical production and application of activation of hydrocarbon bond We are an open, energetic and brave team to challenge ourselves! Here, let's talk with each other and make progress together! Welcome interested students to visit and study in the research group! Recently, Zhao Yingsheng, associate professor and Shi Daqing, Professor of Suzhou University, reported for the first time that using RuCl 3 as catalyst, BNDHP as large hindrance ligand, ferrocene as additive, toluene derivative as alkylating agent, The regioselective C-H alkylation controlled by Ru catalyst system was realized The highlight of the reaction is that the benzyl radicals can be controlled by Ru catalyst and large steric ligands, and the regioselective benzylation takes place in the intermediate or ortho position of 2-arylpyridine, that is to say, the position selectivity of the reaction is controlled by the catalytic system rather than the alkylation reagent Relevant research results were published in ACS Catalysis (ACS catalyst 2017, 7, 4138 − 4143) Figure 1: ruthenium catalyzed o-site selective benzylation (source: acscatal.) then, Zhao Yingsheng, associate professor of research group, reported ruthenium catalyzed m-difluoroalkylation of aromatics In this reaction, various aryls with pyridine, pyrazolyl, imidazolyl or pyrimidine oriented groups can be compatible, and the oxazoline oriented groups that can be removed are reported for the first time, and difluoromethylation products with medium to good yield are obtained In some substrates, Ag (NTF) 2 was used as an additive to improve the yield Difluoromethyl group can be selectively installed in several drug molecules and bioactive compounds Through ethyl difluoroacetate, further functional group transformation can be carried out, which highlights the synthesis effectiveness and importance of this new method Relevant research results were published in org Chem Front., 2017, 4, 1867-1871 Figure 2: ruthenium catalyzed m-difluoroalkylation (source: org Chem Front.) followed by ruthenium catalyzed p-difluoromethylation of acetophenoxime ether with high p-selectivity The site selectivity of the reaction was controlled by the initial screening of the guiding group The reaction can be compatible with many common functional groups, and corresponding para selective difluoroalkylation products can be obtained in medium to good yields Through the mechanism experiment and the research of the research group of Professor Lan Yu of Chongqing University in the aspect of theoretical calculation (DFT), it is shown that the ruthenization metal complex is an important intermediate in the reaction Relevant research results were published in angelwandte Chemie International Edition (angelw Chem Int ed in press) Fig 3: Li Guobao, member of the research group of ruthenium catalyzed para difluoroalkylation of acetophenoxime ether (source: angelw Chem Int ed.), yuan Chunchen, master of 2015 (the first author of ruthenium catalyzed ortho selective benzylation), and doctor of 2017 (the first author of ruthenium catalyzed ortho hydrofluoroalkylation) Http://pubs.acs.org/doi/abs/10.1021/acscalal.7b01072 http://pubs.rsc.org/en/content/articlelanding/2017/qo/c7qo00449d ා! Divabstract http://onlinelibrary.wiley.com/doi/10.1002/anie.201711221/full relevant information of Zhao Yingsheng, Associate Professor: http://web.suda.edu.cn/yszhao/index.html