Coinage metal catalyzed C-H bond functionalization of hydrocarbons

A highlight is given regarding the use of copper-, silver- and gold-based catalysts for the catalytic conversion of unreactive hydrocarbons to a more elaborate and functionalized molecules. An emphasis will given on the reactions where a saturated carbon-hydrogen bond of the hycrocarbon is converted into another functionality. Most often, the overall transformation is composed of the insertion of an X group into the C-H bond followed by a less frequent reaction that assumes the loss of hydrogen in the final product, and finally, the formation of an unsaturated bond which is C=X. The coinage metal-based catalytic systems has an interesting common feature in that it has no M-C and/pr M-H bonds that are formed by any activation process. In addition, a discussion is also given with those catalytic systems that are based on the coinage metals that assumes the functionalization of carbon-hydrogen bonds of nonactivated substrates. The catalytic systems are divided into three types which are: the functionalization by carbene insertion, functionalization by nitrene insertion, and the direct oxidation with a strong oxidant.