Rhodium-catalyzed remote difunctionalization of arenes assisted by a relay directing group

• Published in: Chemical science (Cambridge) Vol. 13; no. 24; pp. 7347 - 7354
• Main Authors: Sun, Lincong, Zhao, Yuyao, Liu, Bingxian, Chang, Junbiao, Li, Xingwei
• Format: Journal Article
• Language: English
• Published: 22-06-2022
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d2sc02205b

Rhodium-catalyzed diverse tandem twofold C-H bond activation reactions of
para
-olefin-tethered arenes have been realized, with unsaturated reagents such as internal alkynes, dioxazolones, and isocyanates being the coupling partner as well as a relay directing group which triggers cyclization of the
para
-olefin group under oxidative or redox-neutral conditions. The reaction proceeded
via
initial
ortho
-C-H activation assisted by a built-in directing group in the arene, and the
ortho
-incorporation of the unsaturated coupling partner simultaneously generated a relay directing group that allows sequential C-H activation at the
meta
-position and subsequent cyclization of the
para
-olefins. The overall reaction represents C-C or N-C difunctionalization of the arene with the generation of diverse 2,3-dihydrobenzofuran platforms. The catalytic system proceeded with good efficiency, simple reaction conditions, and broad substrate scope. The diverse transformations of the products demonstrated the synthetic utility of this tandem reaction.
Rhodium-catalyzed twofold C-H bond activation of
para
-olefin-tethered arenes has been realized using diverse unsaturated reagents. The overall reaction represents C-C or N-C difunctionalization of arenes with the generation of diverse 2,3-dihydrobenzofurans.