5-Benzyloxy-1-phenyltetrazole: Catalytic transfer hydrogenolysis of benzyl ethers

In contrast to the earlier reported inertness of 5-benzyloxy-1-phenyltetrazole, (1a), and 3-benzyloxy-1,2-benzisothiazole 1,1-dioxide, (2a), towards catalytic transfer hydrogenolysis in toluene/water solvent systems, it is now shown that simply changing the solvent to tetrahydrofuran/water leads to their rapid hydrogenolysis with formation of toluene. Compound (1a), C 14 H 12N4O , has a short C-O ether bond to the tetrazole ring [1.3261 (15) A] and a particularly long C-O bond to the benzyl group [1.4676 (16) A], consistent with an activation of this longer bond by the strongly electronegative tetrazole unit.