Fig. 1: Concepts and strategies for the installation of synthetic handles within arenes and their utility.
a, Generic utility of multifunctional synthetic handles within chemical transformations. b, Regiochemical challenges associated with C(sp2)–H functionalization reactions. Pinacolboronic esters have proven broad synthetic utility in a variety of transformations; however, installation by metal-catalysed C(sp2)–H borylation has required innovative strategies for regiocontrol. Bpin, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane. c, Synthetic utility of benzylic trimethylsilanes as masked anion equivalents. Nu, nucleophile. d, Overview of mechanistic pathways for the proposed ruthenium-catalysed C(sp2)–H functionalization leading to regiodivergent outcomes. 1°, primary; 2°, secondary; 3°, tertiary. e, Regiodivergent silylmethylation enabled by a single ruthenium catalyst, [(tBuCN)5Ru(H2O)](BF4)2, providing site-selective access to both ortho- and meta-silylmethylated arenes. f, Reaction conditions for both meta- and ortho-silylmethylation.
