Rhodium(III) and Hexabromobenzene-A Catalyst System for the Cross-Dehydrogenative Coupling of Simple Arenes and Heterocycles with Arenes Bearing Directing Groups
can be used as the cooxidant/catalyst modifier for the [RhIIICp*]‐catalyzed (Cp*=C5Me5) dehydrogenativecross‐coupling of benzamides with simple benzene derivatives (see scheme, DG=directing group). Similarly, heterocycles can be coupled and druglike structures formed. Mechanistic studies suggest a unique and multiple role of the Cu(OAc)2/C6Br6 system and a nonchelate‐assisted CH activation as the
C 6 Br六和 毒品!C 6 Br 6可用作苯甲酰胺与简单苯衍生物的[Rh III Cp *]催化(Cp * = C 5 Me 5)脱氢交叉偶联的助氧化剂/催化剂改性剂(请参见方案,DG =指导基团)。类似地,杂环可以偶联并形成药物样结构。机理研究表明,Cu(OAc)2 / C 6 Br 6系统具有独特的多重作用,而非螯合物辅助的CH活化是决定速率的步骤。
Palladium-Catalyzed Oxidative Arylation of Tertiary Benzamides: <i>Para</i>-Selectivity of Monosubstituted Arenes
A mild and efficient protocol for the high para-selective arylation of monosubstituted arenes with tertiary benzamides has been developed via palladium-catalyzedoxidative coupling reactions. Due to the mild conditions and the easy availability of substrates and oxidant, this method could potentially provide a practical approach for the synthesis of para-substituted biaryl compounds.