Site-Selective Aliphatic C−H Silylation of 2-Alkyloxazolines Catalyzed by Ruthenium Complexes

The Ru-catalyzed dehydrogenative silylation of 2-alkyloxazolines with 1,1,1,3,5,5,5-heptamethyltrisiloxane took place site-selectively at methyl C(sp3)−H bonds located γ to the nitrogen atom of the oxazolyl groups. Pyridine and pyrazole rings could also be used as a directing group. A catalytic mechanism based upon successive σ-bond metathesis is proposed.