The NHBoc group affords ortho selective C-H borylations in arenes and alkenes. Experimental and computational studies support an outer sphere mechanism where the N-H proton hydrogen bonds to a boryl ligand oxygen. The regioselectivities are unique and complement those of directed ortho metalations.
作者:Philipp C. Roosen、Venkata A. Kallepalli、Buddhadeb Chattopadhyay、Daniel A. Singleton、Robert E. Maleczka、Milton R. Smith
DOI:10.1021/ja303443m
日期:2012.7.18
The NHBoc group affords ortho selective C-H borylations in arenes and alkenes. Experimental and computational studies support an outer sphere mechanism where the N-H proton hydrogen bonds to a boryl ligand oxygen. The regioselectivities are unique and complement those of directed ortho metalations.
Modified palladium-catalyzed regioselective ortho-arylation of sp2 C–H bond substrates with a low catalyst loading
substrates such as arylated benzoxazoles, acylated anilines, and pyridines has been developed. The arylation was performed in trifluoroacetic acid (TFA) under air by using PdCl2 as the catalyst with a lowcatalystloading of 1 mol %. And it was found for the first time that the addition of weak base K3PO4 to the acidic solvent could remarkably enhance the reaction rate. The arylated products were isolated