Catalytic Highly Regioselective C–H Oxygenation Using Water as the Oxygen Source: Preparation of 17O/18O-Isotope-Labeled Compounds

We found that the oxygen atom of water is activated to iodosylbenzene derivatives via reversible hydrolysis of PhI(OOCR)2 and can be used to the oxygen source for ruthenium(bpga)-catalyzed site-selective C–H oxygenation. Ru(bpga)/PhI(OOCR)2/H2O system, sterically less bulky methinic and methylenic C–H bonds in various compounds can be converted to desired oxygen functional groups in a site-selective manner. Using this method, oxygen-isotope labeled compounds such as d-[3-17O/18O]-mannose can be prepared in a multigram scale.