Wu Liping group of Lanzhou Institute of Chemical Sciences: synthesis of alkenylborates by dehydroborization and transfer boration of alkenes catalyzed by zirconium

Author: VBE is an important intermediate in synthetic chemistry They have been widely used in the synthesis of bioactive natural products Compared with saturated alkyl borates, carbon carbon double bonds provide more conversion possibilities However, there are some shortcomings in the preparation methods of these compounds, such as the limited source of substrates and the poor compatibility of functional groups In contrast, it is an attractive method to prepare VBE by direct dehydroborization of alkene and borane However, in RH, IR, PD, Ni, Co, Fe and other post transition metal catalytic systems, due to the high borohydride activity of borane, it is easier to form saturated alkyl borates Therefore, it is known that most of the reaction systems need high temperature, or add additional hydrogen acceptors and use diborane to avoid the formation of saturated alkyl borates (Fig 1) Therefore, it is of great value to develop the dehydroborization of alkenes without hydrogen acceptors under mild conditions to prepare alkenylborates efficiently Figure 1: comparison of known methods for preparing alkenylborane with the development strategies of the research group (source: angelw.chem Int ed.) recently, Wu Liping research group, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences A simple and efficient synthesis strategy for preparing alkenylborates was developed based on the dehydroborization of alkenes and boranes catalyzed by pre transition zirconium complexes Firstly, the complex of CP 2 ZrH 2 was synthesized and applied to the catalytic reaction The direct dehydroborization of alkene and borane was realized under the condition of hydrogen free acceptor Most of the reactions can be carried out at room temperature, and can be completed in 10-60 minutes This method not only realizes the direct dehydroborization reaction of aryl substituted alkenes and boranes, but also is effective for long chain alkenes In addition, it is also suitable for substrates with poor tolerance in other precious metal systems Through mechanism study, the authors found that the reaction process is reversible Based on this, they successfully applied zirconium catalyst to transfer boration reaction, thus avoiding the use of borane which is relatively sensitive to air and water in the boration reaction (Fig 2) Figure 2 Zirconium catalyzed transfer boration (source: angelw Chem Int ed.) the research results were recently published on angelw Chem Int ed (DOI: 10.1002 / anie 201908931) The above work has been supported by NSFC, NSFC of Jiangsu Province and National Key Laboratory of carbonyl synthesis and selective oxidation for a long time Recruitment demand: Wu Lipeng, National Key Laboratory of carbonyl synthesis and selective oxidation, Lanzhou Institute of chemistry, Chinese Academy of Sciences, was founded in 2018 The research direction is metal organic catalysis, polymer material catalysis and catalytic application research At present, the main research content is the selective conversion of alkanes and alkenes The research group has been recruiting postdoctoral, research assistant, Ph.D / Master's degree students all the year round We welcome those with lofty ideals and hard work to join the research group Homepage of the research group: https://www.lipengwu-lab.com/ contact: Tel: 15116931657 email: lipengwu@licp.cas.cn