Cycloruthenation of aryl imines and N-heteroaryl benzenes via C-H bond activation with Ru(II) and acetate partners.

International audienceThe reaction of arylimines with [RuCl2(p-cymene)]2 and 4 equiv. of KOAc at room temp. in methanol leads to the formation of N-Ru-C cycloruthenates RuCl(arylimine-kC,N)(p-cymene) 3a-3d via ortho C-H activation/deprotonation by acetate. The presence of the stable Ru-Cl bond rather than a labile Ru-OAc bond is crucial for the isolation of the complexes. This preparative method of cyclometallates was applied to 2-phenyloxazoline, and benzo[h]quinoline and to the improved synthesis of 2-phenylpyridine and 1-phenylpyrazole derivs. The mol. structures of three cycloruthenates are reported