High oxidation state organomolybdenum and organotungsten chemistry in protic environments

The chemistry of organomolybdenum and -tungsten compounds in high oxidation states (mostly V and VI) is reviewed, with special attention on the behaviour in protic media and with respect to protic reagents. The high metal–carbon bond covalency imparts a great degree of inertness to these bonds relative to protonolysis. Hence, extensive chemistry in a wide variety of media and with protic reagents is possible without affecting the metal–(hydrocarbyl ligand) interactions. This article does not cover metallocene [i.e. bis(cyclopentadienyl)], alkylidene and alkylidyne derivatives, that have been extensively covered in other recent reviews.