Ambient temperatureruthenium‐catalyzedC−H arylations were accomplished by visiblelight without additional photocatalysts. The robustness of the ruthenium‐catalyzedC−H functionalization protocol was reflected by a broad range of sensitive functional groups and synthetically useful pyrazoles, triazoles and sensitive nucleosides and nucleotides, as well as multifold C−H functionalizations. Biscyclometalated
Recyclable Ruthenium Catalyst for Distal
<i>meta</i>
‐C−H Activation
作者:Isaac Choi、Valentin Müller、Yanhui Wang、Kai Xue、Rositha Kuniyil、Loren B. Andreas、Volker Karius、Johan G. Alauzun、Lutz Ackermann
DOI:10.1002/chem.202003622
日期:2020.11.26
unprecedented hybrid‐ruthenium catalysis for distal meta‐C−H activation. The hybrid‐ruthenium catalyst was recyclable, as was proven by various heterogeneity tests, and fully characterized with various microscopic and spectroscopic techniques, highlighting the physical and chemical stability. Thereby, the hybrid‐ruthenium catalysis proved broadly applicable for meta‐C−Halkylations of among others purine‐based
structurally complex structures. During the past decade, directing groups have revolutionized molecular synthesis in terms of ortho-selective C–H activation. In sharp contrast, a selectivity switch that guides the typical ortho- to remote meta-C–H activation has thus far proven elusive. Herein, we describe the realization of such a concept for a robust selectivity control in rutheniumcatalysis. The distal
derivatives were accomplished by versatile ruthenium catalysis. Thus, the arene‐ligand‐free complex [Ru(OAc)2(PPh3)2] enabled remote C−H functionalizations with ample scope and excellent levels of chemo‐ and positional selectivities. Detailed experimental and computational mechanistic studies provided strong support for a facile C−H activation within a ruthenium(II/III) manifold.