para-Selective C–H functionalization of pyridines holds a significant value but remains underdeveloped. Site-switchable C–H functionalization of pyridines under easily tunable conditions expedites drug development. We recently reported a redox-neutral dearomatization–rearomatization strategy for meta-C–H functionalization of pyridinesvia oxazino pyridine intermediates. Here, we demonstrate that these
Ruthenium-Catalyzed Conversion of sp<sup>3</sup> C–O Bonds in Ethers to C–C Bonds Using Triarylboroxines
作者:Yohei Ogiwara、Takuya Kochi、Fumitoshi Kakiuchi
DOI:10.1021/ol2012007
日期:2011.6.17
Catalytic conversion of unreactive sp(3) C-O bonds in alkyl ethers to C-C bonds is described. Alkyl ethers bearing 2- or 4-pyridyl groups were coupled with triarylboroxines in the presence of a ruthenium catalyst. Triarylboroxines bearing a variety of functional groups including electron-withdrawing and -donating groups can be used for the reaction. No additional base was required for the coupling with the organoboron reagents, and base-sensitive groups can be tolerated. The reaction is considered to proceed via dehydroalkoxylation followed by addition of triarylboroxines to form C-C bonds.
C-H Bond Activation by a Ruthenium(II) <i>β</i>
-Diketonate Complex: A Mechanistic Study
作者:Anamarija Briš、Iztok Turel、Jana Roithová
DOI:10.1002/ejoc.201800787
日期:2018.12.2
2‐Phenylpyridine C–H activation catalysed by a ruthenium(II) β‐diketonate complex was studied by ESI‐MS and CID. We have identified [Ru(β‐diketonate)(CTPhPy)Cl]+ as an active intermediate, and its collisional activation leads to C–H activation. DFT calculations were performed to identify all ruthenium intermediates along the C–H activation reaction pathway.