Palladium associated with cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane (Tedicyp) was found to promote the direct 2-arylation of a variety of thiophene derivatives via CH functionalisation in good yields using very lowcatalystloadings. Electron-deficient, electron-excessive or sterically-congested aryl bromides are tolerated. Moreover, several substituents on the aryl bromide
The directarylation of activated thiophenes was accomplished in moderate to good yields using a Heck-type reaction with the mixture of Pd(OAc)2 and n-Bu4NBr as a catalyticsystem. This new arylation method is applied to different derivatives and has proved to be compatible with sensitive functional groups. Furthermore, the substituent nature and position on the thiophene moiety influence the cross
使用Heck型反应,将Pd(OAc)2和n- Bu 4 NBr的混合物作为催化体系,可以中等至良好的产率完成活化噻吩的直接芳基化反应。这种新的芳基化方法适用于不同的衍生物,并已证明与敏感的官能团兼容。此外,噻吩部分上的取代基性质和位置影响交叉偶联。特别是当杂环在第2位被吸电子基团取代时,该取代是区域特异性的。
Directthiophenearylation using a Heck-type reaction with as catalytic system is reported. Reactions with 2- and 3-substituted thiophenes have shown that substituent nature and position influence the cross-coupling. In particular, the substitution is regiospecific when the heterocycle is 2-substituted with an electron withdrawing group.
Bis(imino)acenaphthene (BIAN)-Supported <i>N</i>-Heterocyclic Carbene Palladium Complexes with Ancillary Ligands: Readily Activated Precatalysts for Direct C–H Arylation of Thiophenes
作者:Di-Zhong Zheng、Dong-Hui Li、Huan Liu、Youxiang Shao、Zhuofeng Ke、Feng-Shou Liu
DOI:10.1021/acs.organomet.2c00007
日期:2022.4.25
thiophenes with (hetero)aryl bromides by bulky bis(imino)acenaphthene (BIAN)-supported N-heterocyclic carbene palladiumcomplexes. The relationship between the structure of palladiumcomplexes with ancillary ligands and catalytic properties was discussed. Upon a low palladium loading of 0.01–0.05 mol %, the bulky palladiumcomplex was successfully used to catalyze the cross-coupling of a variety of thiophens