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.
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.
Co(III)-Catalyzed Synthesis of Quinazolines via C–H Activation of <i>N</i>-Sulfinylimines and Benzimidates
作者:Fen Wang、He Wang、Qiang Wang、Songjie Yu、Xingwei Li
DOI:10.1021/acs.orglett.6b00227
日期:2016.3.18
as a synthon of nitriles, and subsequent coupling with arenes such as N-sulfinylimines and benzimidates bearing a functionalizable directing group provided facile access to two classes of quinazolines under Co(III)-catalysis.