C-H nitrogenation and oxygenation by ruthenium catalysis.

Remarkable recent progress has been accomplished in direct C-H functionalizations for the formation of C-N and C-O bonds through the use of readily accessible ruthenium catalysts. Particularly, ruthenium(II) complexes allowed for challenging direct C(sp(2))-H hydroxylation of arenes. These catalysts set the stage for step-economical C-H functionalization with electron-rich as well as electron-deficient (hetero)arenes and, therefore, provided versatile access to diversely decorated phenols. While a number of synthetically useful protocols for ruthenium-catalyzed C(sp(3))-H bond nitrogenation have been elaborated, the analogous transformations of more stable C(sp(2))-H bonds were very recently achieved.