Photoredox/Cobalt Dual Catalysis for Visible-Light-Mediated Alkene–Alkyne Coupling
作者:Pramod Rai、Kakoli Maji、Biplab Maji
DOI:10.1021/acs.orglett.9b01201
日期:2019.5.17
Dual photoredox transition-metal catalysis has recently emerged as a powerful tool for making synthetically challenging carbon–carbon bonds under milder reaction conditions. Herein, we report on the visible-light-mediated controlled generation of low-valent cobalt catalyst without the need for a metallic reductant. It enabled C–C bondformation via ene-yne coupling at roomtemperature. The generality
Palladium-catalyzed remote C–H functionalization of 2-aminopyrimidines
作者:Animesh Das、Akash Jana、Biplab Maji
DOI:10.1039/d0cc00575d
日期:——
A straightforward strategy was developed for the arylation and olefination at the C5-position of the N-(alkyl)pyrimidin-2-amine core with readily available aryl halides and alkenes, respectively. This approach was highly regioselective, and the transformation was achieved based on two different (Pd(ii)/Pd(iv)) and (Pd(0)/Pd(ii)) catalytic cycles.
Enantioselective Pallada‐Electrocatalyzed C−H Activation by Transient Directing Groups: Expedient Access to Helicenes
作者:Uttam Dhawa、Cong Tian、Tomasz Wdowik、João C. A. Oliveira、Jiping Hao、Lutz Ackermann
DOI:10.1002/anie.202003826
日期:2020.8.3
Asymmetric pallada‐electrocatalyzed C−H olefinations were achieved through the synergistic cooperation with transient directing groups. The electrochemical, atroposelective C−H activations were realized with high position‐, diastereo‐, and enantio‐control under mild reaction conditions to obtain highly enantiomerically‐enriched biaryls and fluorinated N−C axiallychiral scaffolds. Our strategy provided
A ruthenium‐catalyzed ortho‐alkenylation of acylgermanes with electron‐deficient alkenes through direct C–H bond activation has been developed. With acylgermane as the directing group, this method provides a straightforward access to diverse acylgermanes derivatives with good functional group tolerance and site‐selectivity under mild reaction conditions.
Ruthenium(<scp>ii</scp>) oxidase catalysis for C–H alkenylations in biomass-derived γ-valerolactone
作者:Alexander Bechtoldt、Marcel E. Baumert、Luigi Vaccaro、Lutz Ackermann
DOI:10.1039/c7gc03353b
日期:——
Ruthenium(II) biscarboxylate oxidasecatalysis is a powerful tool for the assembly of functionalized arenes with oxygen as a green oxidant, but this strategy was thus far limited to its use in traditional organic solvents. Herein, we report on a green procedure for the ruthenium(II) biscarboxylate-catalysed C–H functionalisation in biomass-derived γ-valerolactone as the reaction medium. The oxidase