Blue Light Promoted Difluoroalkylation of Aryl Ketones: Synthesis of Quaternary Alkyl Difluorides and Tetrasubstituted Monofluoroalkenes
作者:Kangkui Li、Jingchao Chen、Chunhui Yang、Keyang Zhang、Chunxiang Pan、Baomin Fan
DOI:10.1021/acs.orglett.0c01294
日期:2020.6.5
cost-effective method for the preparation of fluoroalkylated compounds has been described by the direct photoexcitation of halofluoroalkanes with blue light absorptivity, enabling the difluoroalkylation of arylketones. The methodology has provided an efficient, mild, and catalyst-free synthetic method for quaternary difluoroalkylated arenes and tetrasubstituted monofluoroalkenes.
Highly stereoselective nickel-catalyzed difluoroalkylation of aryl ketones to tetrasubstituted monofluoroalkenes and quaternary alkyl difluorides
作者:Chao Li、Yi-Xuan Cao、Ruo-Xing Jin、Kang-Jie Bian、Zi-Yang Qin、Quan Lan、Xi-Sheng Wang
DOI:10.1039/c9sc02806d
日期:——
stereo-defined tetrasubstituted monofluoroalkenes or quaternary alkyl difluorides from secondary or tertiary ketones, respectively, has been established. Mechanistic investigations indicated that these C-H fluoroalkylations proceed via a Ni(i)/Ni(iii) catalytic cycle. An obvious fluorine effect was observed in the reaction, and this reaction has demonstrated high stereoselectivity, mild conditions, and broad
Copper-catalyzed asymmetric hydrogenation of 2-substituted ketones <i>via</i> dynamic kinetic resolution
作者:Olga V. Zatolochnaya、Sonia Rodríguez、Yongda Zhang、Kendricks S. Lao、Sergei Tcyrulnikov、Guisheng Li、Xiao-Jun Wang、Bo Qu、Soumik Biswas、Hari P. R. Mangunuru、Daniel Rivalti、Joshua D. Sieber、Jean-Nicolas Desrosiers、Joyce C. Leung、Nelu Grinberg、Heewon Lee、Nizar Haddad、Nathan K. Yee、Jinhua J. Song、Marisa C. Kozlowski、Chris H. Senanayake
DOI:10.1039/c8sc00434j
日期:——
A new class of tunable heterophosphole dimeric ligands have been designed and synthesized. These ligands have enabled the first examples of Cu-catalyzed hydrogenation of 2-substituted-1-tetralones and related heteroaryl ketones via dynamic kinetic resolution, simultaneously creating two contiguous stereogenic centers with up to >99 : 1 dr and 98 : 2 er. The ligand-Cu complexes were isolated and characterized
设计并合成了一类新型可调节杂磷二聚体配体。这些配体通过动态动力学拆分实现了铜催化 2-取代-1-四氢萘酮和相关杂芳基酮氢化的第一个例子,同时产生了两个连续的立体中心,其高达 >99 : 1 dr 和 98 : 2 er。通过单晶 X 射线分离并表征了配体-Cu 配合物,DFT 计算揭示了一种新型杂配二聚氢化铜过渡态。
RuPHOX–Ru catalyzed asymmetric hydrogenation of α-substituted tetralones <i>via</i> a dynamic kinetic resolution
The efficient RuPHOX–Ru catalyzed asymmetric hydrogenation of α-substituted tetralones via a dynamic kineticresolution has been achieved for the synthesis of chiral tetrahydronaphthols. The mechanism study indicated that hydrogenation with H2 gas, rather than transfer hydrogenation with EtOH solvent as the hydrogen source, predominates in the reaction pathway.