Facile Hydrogenative Deprotection of N‑Benzyl Groups Using a Mixed Catalyst of Palladium and Niobic Acid-on-Carbon
journal contributionposted on 05.02.2020, 09:29 by Yuta Yamamoto, Eisho Shimizu, Kazuho Ban, Yoshiyuki Wada, Tomoteru Mizusaki, Masatoshi Yoshimura, Yukio Takagi, Yoshinari Sawama, Hironao Sajiki
The palladium-on-carbon (Pd/C)-catalyzed hydrogenative deprotection of the N-benzyl-protecting group was effectively facilitated by the combined use of niobic acid-on-carbon (Nb2O5/C). Nb2O5/C is an acidic heterogeneous catalyst prepared from NbCl5 and activated carbon. The catalysts were easily removed from the reaction mixture and reusable. Deprotected amines were obtained in excellent yields without an additional neutralization process. The facilitating effect of Nb2O5/C was also observed during the Pd/C-catalyzed hydrogenative deprotection of the N-benzyloxycarbonyl (Cbz) and O-benzyl groups.