Vanadium secondary synthesis

Vanadium-Containing Molecular Sieves by Secondary Synthesis. . 208... 

To avoid secondary reductive steps, low concentrations of the active low-valent metal are advantageous, i.e. the use of catalytic one-electron reduction cycles [31]. Low-valent vanadium species are efficient catalysts for pinacolization. After the primary electron transfer, the oxidized vanadium catalyst can be reduced by Zn(0) or by aluminum [32], TrialkyIsilanes have to be added to decomplex the oxidized vanadium catalyst from the pinacol [33]. The same catalytic system can also be used for the synthesis of 1,2-diamines via coupling of aldimines [34]. Alternatively, a titanium (Il)-samarium system gives the 1,2-diamines with moderate D,L-selectivity [35]. 

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