The first example of oxidant-free cobalt-catalyzed synthesis of five-membered spirocycles is reported from benzimidates and maleimides utilizing nitrobenzene as promoter. In contrast to previously known cobalt-catalyzed oxidative C–H functionalization reactions, this transformation occurs efficiently in the absence of oxidant and is accompanied by liberation of hydrogen. The spiro-lactams were readily
Synthesis of 1<i>H</i>-Indazoles from Imidates and Nitrosobenzenes via Synergistic Rhodium/Copper Catalysis
作者:Qiang Wang、Xingwei Li
DOI:10.1021/acs.orglett.6b00727
日期:2016.5.6
Nitrosobenzenes have been used as a convenient aminating reagent for the efficient synthesis of 1H-indazoles via rhodium and copper catalyzed C–H activation and C–N/N–N coupling. The reaction occurred under redox-neutral conditions with high efficiency and functional group tolerance. Moreover, a rhodacyclic imidate complex has been identified as a key intermediate.
Synthesis of Highly Fused Pyrano[2,3-<i>b</i>]pyridines via Rh(III)-Catalyzed C–H Activation and Intramolecular Cascade Annulation under Room Temperature
作者:Xu Han、Feng Gao、Chunpu Li、Daqing Fang、Xiong Xie、Yu Zhou、Hong Liu
DOI:10.1021/acs.joc.9b03102
日期:2020.5.15
A facile access to the polycyclic-fused pyrano[2,3-b]pyridines has been established under room temperature via Rh(III)-catalyzed C-H bond activation and intramolecular cascade annulation. This strategy features high efficiency, unique versatility, and generality and it can occur under mild conditions in good to excellent yields. More importantly, this strategy can be extended to the late-stage functionalization
Rh(III)-Catalyzed C–C/C–N Coupling of Imidates with α-Diazo Imidamide: Synthesis of Isoquinoline-Fused Indoles
作者:He Wang、Lei Li、Songjie Yu、Yunyun Li、Xingwei Li
DOI:10.1021/acs.orglett.6b01284
日期:2016.6.17
Imidate esters and diazo compounds have been established as bifunctional substrates for the construction of biologically active fused heterocycles viarhodium-catalyzed C–H activation and C–C/C–N coupling. This reaction occurs undermildconditions with high efficiency, step economy, and low catalyst loading.
and expeditious protocol for the synthesis of diverse difunctionalized indenones through rhodium-catalyzed C–H activation and multistep cascade reaction of benzimidates and alkenes has been developed. The transformation involves the cleavage and formation of multiple bonds in one pot under mild reaction conditions, and Mn(OAc)2 plays an important role in the reaction.