Thermocatalytic Dehydrogenation-Enabled Arene-Alkane Couplings

The direct use of non-prefunctionalized arene and alkane as the starting materials to construct C-aryl-C-alkyl bond is an unfulfilled target and approaches to this challenge rarely surface in methodology studies. Current methods for thermocatalytic arene-alkane couplings (AAC) occur with specific substrates and/or inconvenient reagents. Herein, we report a one-pot relay bicatalysis system for AAC involving (pincer)Ir-catalyzed alkane transfer dehydrogenation and Fe(OTf)(3)-catalyzed olefin hydroarylation. This system exhibits broad scope and is particularly effective for alkylation of arenes with arylalkanes to form 1,1-diarylalkanes with high chemo- and regioselectivity, making it potentially useful for late-stage alkylation of complex molecules. Experimental mechanistic data provide a view into the factors controlling the regioselectivity. Finally, the strategy of dehydrogenation-enabled arene-alkane couplings has been successfully extended to a tandem catalysis by using a heterogeneous olefin hydroarylation catalyst.

Automated summary

Here we report a one-pot relay bicatalysis system for constructing C-aryl-C-alkyl bonds using (pincer)Ir-catalyzed alkane transfer dehydrogenation and Fe(OTf)(3)-catalyzed olefin hydroarylation. This system exhibits broad scope and high selectivity for the alkylation of arenes with arylalkanes, making it potentially useful for late-stage alkylation of complex molecules. Experimental mechanistic data provide insights into the factors controlling the regioselectivity.