Ghosh Pradip, Schoch Roland, Bauer Matthias, Jacobi von Wangelin Axel
Dept. of Chemistry, University of Hamburg, Martin Luther King Pl 6, 20146, Hamburg, Germany.
Dept. of Chemistry, Center for Sustainable Systems Design, CSSD, University of Paderborn, 33098, Paderborn, Germany.
Angew Chem Int Ed Engl. 2022 Jan 3;61(1):e202110821. doi: 10.1002/anie.202110821. Epub 2021 Nov 22.
Metal-catalyzed C-H activations are environmentally and economically attractive synthetic strategies for the construction of functional molecules as they obviate the need for pre-functionalized substrates and minimize waste generation. Great challenges reside in the control of selectivities, the utilization of unbiased hydrocarbons, and the operation of atom-economical dehydrocoupling mechanisms. An especially mild borylation of benzylic CH bonds was developed with the ligand-free pre-catalyst Co[N(SiMe ) ] and the bench-stable and inexpensive borylation reagent B pin that produces H as the only by-product. A full set of kinetic, spectroscopic, and preparative mechanistic studies are indicative of a tandem catalysis mechanism of CH-borylation and dehydrocoupling via molecular Co catalysts.
金属催化的C-H活化是构建功能分子的具有环境和经济吸引力的合成策略，因为它们无需预官能化的底物，并将废物产生降至最低。在选择性控制、无偏烃的利用以及原子经济脱氢偶联机制的操作方面存在巨大挑战。使用无配体预催化剂Co[N(SiMe ) ]和稳定且廉价的硼化试剂B pin开发了一种特别温和的苄基CH键硼化反应，该反应仅产生H作为唯一副产物。一整套动力学、光谱学和制备机理研究表明，通过分子钴催化剂进行CH硼化和脱氢偶联的串联催化机理。
