Preyssler heteropolyacid H14[NaP5W29MoO110]: A heterogeneous, green and recyclable catalyst used for the protection of functional groups in organic synthesis

GUSTAVO ROMANELLI; DIEGO RUIZ; PATRICIA VÁZQUEZ; HORACIO THOMAS; JUAN AUTINO

CHEMICAL ENGINEERING JOURNAL

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2010 vol. 161 p. 355 - 362

1385-8947

Efficient protection of alcohols, phenols, amines, thiols and aldehydes has been carried out under catalysis by the highly active Preyssler heteropolyacidH14[NaP5W29MoO110] (H14PMo). In this paper we report the catalytic activity of bulk H14PMo in each procedure to form: 2 tetrahydropyranyl acetals of alcohols and phenols, working at room temperature and using toluene as solvent; aldehyde 1,1-diacetates (acylals), a solvent-free preparation using Ac2O at room temperature; alcohol acetates, phenols, amines and thiols, working at room temperature, using toluene as solvent and Ac2O as acetylating agent; benzhydryl-ethers from the reaction of alcohols or phenols and diphenylmethanol, in toluene at 60–80 ◦C; and silylation of phenol and alcohols with hexamethyldisilazane as silylating agent in toluene at 85 ◦C. All the described procedures provide useful alternatives for performing the protection of different functional groups, which are general, rapid, selective and inexpensive, and have a low environmental impact. The catalyst was easily recovered and reusable in all of the described procedures, without loss of its catalytic activity.