Targeting a distant C–H bond

Organic Chemistry Enzymes often have intricate active sites that bind one portion of a molecule to orient a distant portion for optimal reactivity. This type of orienting effect has proven a much greater challenge for small-molecule catalysts. Reyes et al. now report a simple ligand that can simultaneously bind to an iridium catalyst through a pyridine substituent while positioning an amide or ester reactant through a hydrogen-bonding urea. As a result, the catalyst exclusively borylates the site three carbons away from the carbonyl, with a second chiral ligand inducing high enantioselectivity. Science , this issue p. [970][1] [1]: /lookup/doi/10.1126/science.abc8320