Ruthenium- and Rhodium-Catalyzed Chemodivergent Couplings of Ketene Dithioacetals and α-Diazo Ketones via C-H Activation/Functionalization.

Chemodivergent coupling of α-acylketene dithioacetals with diazo compounds has been realized under catalyst control. The Ru(II)-catalyzed C-H activation occurred at the olefinic position, and 1:2 coupling with α-diazoketoesters leads to furfurylation. In contrast, the Rh(III)-catalyzed C-H functionalization occurred at both the olefinic and the ortho C(aryl)-H positions, and [4 + 2] annulation afforded naphthalenones. Synthetic applications have been performed to demonstrate the usefulness of the coupling system.