Titanium-Catalyzed Exhaustive Reduction of Oxo-Chemicals.

Catalytic reduction of carboxylic acids and derivatives all the way to their corresponding methyl-compounds is very rare and still challenging for homogeneous transition-metal catalysis. Herein, we report an unprecedented and general catalytic exhaustive reduction of carboxylic functional group straightforwardly to a methyl group. This reaction was achieved using earth-abundant and readily available titanium as a catalyst. Our system has broad functional group tolerance and works for various other types of oxo-chemicals such as alcohols, aldehydes, ketones, lactones, and carboxylates (>100 examples). Preliminary mechanistic studies revealed that the in situ-generated Ti III -H species was vital for this transformation.