Site--selective and stereoselective C(sp 3 )-H borylation of alkyl side chains of 1,3--azoles with bis(pinacolato)diboron was effectively catalyzed by a silica--supported monophosphine--Ir catalyst. The borylation occurred under relatively mild conditions (2 mol% Ir, 50-90 °C), affording the corresponding primary and secondary alkylboronates. This system was applicable to a variety of 1,3--(benzo)azoles such as thiazoles, oxazoles, and imidazoles.