Tetrahydropyranyl protection and deprotection of alcohols using a niobium-based Brønsted acid catalyst

Abstract

Crites, CL.; Lima, FM.; Marín García, ML.; Netto Ferreira, JC.; Impellizzeri, S.; HallettTapley, GL.; Scaiano, JC. (2016) Abstract. Niobium phosphate (NbPO4) was used as a heterogeneous catalyst in the protection of a series of aliphatic alcohols as tetrahydropyranyl (THP) derivatives.Protection of primary alcohols using this material with strong Brønsted acid sites was achieved in good yields (75-94%), while moderate values were obtained in the protection of secondary and tertiary alcohols (50-84%), largely dependent on the steric hindrance in the proximity of the hydroxyl moiety. NbPO4 also catalyzed deprotection of THP ethers derived from primary alcohols and phenol with moderate yields (65-99%).2