Alkanes are an abundant and valuable resource for transformation into value-added fine chemicals.However, selective functionalization of specific C(sp 3 )-H bonds in alkanes is a significant challenge, particularly for alkyl-alkyl bond formation, due to the small differences in reactivity between the various C(sp 3 )-H bonds in alkanes and their intrinsic inertness. Herein, we report a silver-catalyzed site-selective C(sp 3 )-H benzylation of simple alkanes using N-triftosylhydrazones as a convenient carbene precursor, which enables the synthesis of diverse array of alkylated aromatics. The reaction proceeds under mild conditions to afford high-value-added alkylarenes in generally high yields, with exquisite site selectivity and good functional group compatibility. A one-pot two-step protocol starting from aldehydes was also realized, thereby constituting a formal reductive alkylation of aryl aldehydes by alkanes. Experimental investigations and DFT calculations reveal that the role of the Tp Br3 Ag catalyst is threefold: it modulates the carbene reactivity, inhibits carbene dimerization, and avoids over-insertion of the product. All three aspects are crucial for the success of this first site-selective intermolecular insertion of donor carbenoids into C(sp 3 )-H bonds of simple alkanes. Methods Supporting InformationDetailed information about the experimental procedures as well as analytical data is provided in the Supplementary Information.

A silver-mediated [3 + 2] cycloaddition of "CNN" and "CC" for constructing pyrazoles has been described. The "CNN" building block used is N-isocyanoiminotriphenylphosphorane, which is a stable, safe, easy-to-handle, and odorless solid isocyanide. The reaction is characterized by its mild conditions, broad substrate scope, and excellent functional group tolerance.