Copper-Catalyzed Direct sp² C–H Silylation of Arylamides Using Disilanes

Abstract

A copper-catalyzed method for direct intermolecular ortho-silylation of benzamides has been developed that affords organosilane products in moderate to high yields. The key features include: (i) use of commercially available disilanes as a silicon source with 8-aminoquinoline as a bidentate directing group, (ii) use of earth-abundant first-row transition metal, (iii) operationally simple conditions without the need of an inert atmosphere, and (iv) tolerance of a wide range of functional groups. The practicality and effectiveness of this method have been demonstrated by a gram-scale experiment. This strategy, therefore, constitutes a convenient way of constructing C−Si bonds useful for synthetic organic chemistry.

Palladium-Catalyzed ortho-C(sp2)–H Silylation of Aromatic Ketones Using an Aminooxyamide Auxiliary

“…Moreover, remote meta - and para -selective C­(sp 2 )–H silylation using palladium catalysis and directing group strategy were also reported . More recently, a copper-catalyzed method for direct intermolecular ortho -silylation of benzamides with 8-aminoquinoline was developed . Notably, silylation of ortho -C­(sp 2 )–H bonds of aromatic ketones has never been reported.…”

Regio- and Diastereoselective [3 + 2]-Spiroannulation of Benzoxazines with Chalcones: A Rh(III)-Catalyzed Redox-Neutral Approach to α-Aroyl Spiro-Indanamines

“…To circumvent the problem, we were primarily attracted by the observation that rhodium-catalyzed C–H activation plays pivotal roles in [3 + 2]-annulation chemistry, generating unique cyclic structures in a regio- and stereoselective manner. − ,− ,− In continuation with our research endeavors in transition-metal-catalyzed C–H functionalization for the efficient construction of functionalized heterocycles, ,, we herein wish to report a redox-neutral rhodium-catalyzed tandem C–H activation/[3 + 2]-annulation cascade reaction between benzoxazines and chalcones for a highly diastereoselective synthesis of a series of novel spirocycles containing three consecutive stereogenic centers (Scheme b). In the process, we have also demonstrated the capability of imine-ligated half-sandwich rhodacycle complex intermediates in this spiroannulation strategy.…”