State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences , University of Chinese Academy of Sciences , 190 Kaiyuan Avenue , Guangzhou 510530 , China.
Department of Chemistry , Jinan University , Huangpu Road West 601 , Guangzhou 510632 , China.
Org Lett. 2018 Apr 6;20(7):1832-1836. doi: 10.1021/acs.orglett.8b00346. Epub 2018 Mar 9.
A Pd-catalyzed site-selective C(sp)-H activation/cycloimidoylation of 2-isocyano-2,3-diarylpropanoates to construct diverse cyclic imine products has been developed. Six-membered 3,4-dihydroisoquinolines containing a C3 quaternary carbon center were generated dominantly by using bulky AdP n-Bu as a ligand, while five-membered 1,1-disubstituted 1 H-isoindoles were formed preferentially in the presence of bidentate phosphine ligand DPPB. The selectivity for 1 H-isoindole formation was enhanced by using steric hindered aryl iodides. DFT calculations suggested that the experimentally observed ligand-controlled selectivity was a result of trans effect.
钯催化的 2-异氰基-2,3-二芳基丙二酸酯的 C(sp)-H 活化/环亚胺化反应,构建了多种环状亚胺产物。使用大位阻 AdP n-Bu 作为配体,主要生成含有 C3 季碳中心的六元 3,4-二氢异喹啉,而在双齿膦配体 DPPB 的存在下,则优先形成五元 1,1-二取代 1 H-茚满。使用空间位阻芳基碘化物可以增强 1 H-茚满形成的选择性。DFT 计算表明,实验观察到的配体控制的选择性是反式效应的结果。