Titanium nitride-catalyzed reduction

A high selectivity and activity for Z-stilbene was observed in the titanium nitride-catalyzed reduction in solution with hydride NaAlH4 as a reducing agent (Figure 2.7) [56]. Filtration tests, recycling of the catalysts, and NMR data indicated that the reaction mechanism is heterogeneous, with hydroalumination intermediates formed in the course of the reduction. 

Figure 2.7 Titanium nitride-catalyzed reduction in solution with hydride NaAIH4[56]. (Reproduced with permission from Elsevier.)...

The DPE reduction is used as a test reaction to characterize the materials and optimize the preparation conditions of the catalyst. Since hydroaluminations can also be used for the synthesis of carboxylic acids, deuterated products, or vinyl halides via quenching with CO2, D2O or Br2 [44], the method is also a valuable organic synthesis tool. However, as compared with molecular catalysts like Cp2TiCl2 that are known to catalyze hydroaluminations [44], the titanium nitride materials described here are solid catalysts and can be separated by centrifugation. Moreover, they can be reused several times, which is an advantage as compared to molecular catalysts. 

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