The ubiquity of C-H bonds makes their selective activation a challenge of significant current interest. Recent developments have revealed that C-H activation can happen at ambient temperatures, whether by metal catalysts, radical-type reactivity or carbenoid/nitrenoid activation (J. C.-K. Chu and T. Rovis, Angew. Chem. Int. Ed. 2018, 57, 62). The emerging challenge is site selectivity – developing synthetically useful transformations on molecules that have an abundance of C-H bonds through catalyst control. Recent efforts at effecting such transformations with regiocomplementarity, as well as diastereo- and enantioselectivity will be the subject of this lecture.