A highly efficient base-, metal-, and oxidant-free catalytic O–H insertion reaction of diazoalkanes and phosphinic acids in the presence of B(C6F5)3 has been developed. This powerful methodology provides a green approach towards the synthesis of a broad spectrum of α-phosphoryloxy carbonyl compounds with good to excellent yields (up to 99% yield). The protocol features the advantages of operational
Highly enantioselective trapping of zwitterionic intermediates by imines
作者:Huang Qiu、Ming Li、Li-Qin Jiang、Feng-Ping Lv、Li Zan、Chang-Wei Zhai、Michael P. Doyle、Wen-Hao Hu
DOI:10.1038/nchem.1406
日期:2012.9
trap the zwitterionic intermediates. Here, we describe the use of imines, activated by chiral organocatalysts, and a highly efficient integrated rhodium and chiralBrønstedacid co-catalysed process to trap zwitterionic intermediates that have been proposed previously to undergo a formal C–H insertion reaction, allowing us to obtain polyfunctionalized indole and oxindole derivatives in a single step
New reaction of enamines with aryldiazoacetates catalyzed by transition metal complexes
作者:Wei-Jie Zhao、Ming Yan、Dan Huang、Shun-Jun Ji
DOI:10.1016/j.tet.2005.03.093
日期:2005.6
The reaction of aryldiazoacetates with enamines catalyzed by copper and rhodium complexes provided γ-keto esters in good yields. A full investigation of the effects of solvents, catalysts, enamines and aryldiazoacetates on the reaction was carried out. Careful analysis of the crude reaction mixture revealed a substituted enamine as the primary product, which was hydrolyzed over silica gel to give a
Iron-catalyzed intermolecular cycloaddition of diazo surrogates with hexahydro-1,3,5-triazines
作者:Pei Liu、Chenghao Zhu、Guangyang Xu、Jiangtao Sun
DOI:10.1039/c7ob02115a
日期:——
We report here an unprecedented iron-catalyzed cycloaddition reaction of diazo surrogates with hexahydro-1,3,5-triazines, providing five-membered heterocycles in moderate to high yields under mild reaction conditions. This cycloaddition features C–N and C–C bond formation using a cheap iron catalyst. Importantly, different to our former report on a gold-catalyzed system, both donor/donor and donor/acceptor
Gold‐Catalyzed Formal [4+1]/[4+3] Cycloadditions of Diazo Esters with Triazines
作者:Chenghao Zhu、Guangyang Xu、Jiangtao Sun
DOI:10.1002/anie.201606139
日期:2016.9.19
gold‐catalyzed formal [4+1]/[4+3] cycloadditions of diazo esters with hexahydro‐1,3,4‐triazines, thus providing five‐ and seven‐membered heterocycles in moderate to high yields under mild reaction conditions. These reactions feature the use of a gold complex to accomplish the diverse annulations and the first example of the involvement of a gold metallo‐enolcarbene in a cycloaddition. It is also the