Sulphated zirconia as an eco-friendly catalyst in acylal preparation under solvent-free conditions, acylal deprotection assisted by microwaves, and the synthesis of anhydro-dimers of o-hydroxybenzaldehydes.
A solvent-free approach is described for the regioselective synthesis of acylals (1,1-diacetates) in shorter reaction times and higher yields, compared to conventional methodology using solvents. In the protection reaction of the o-hydroxybenzaldehyde the formation of acetyl compounds and anhydro-dimers was observed. The deprotection reaction involves microwave (MW) exposure of diluted reactants in the presence of solid sulphated zirconia (SZ) catalyst that can be easily recovered and reused. The sulphated zirconia was recycled several times without any loss of activity.
Palacios-Grijalva
Laura Nadxieli
LN
Departamento de Ciencias Básicas, UAM-A, Av. San Pablo, No. 180. C.P. 02200, México, D.F., Mexico. lnpg@correo.azc.uam.mx
Cruz-González
Deysi Y
DY
Lomas-Romero
Leticia
L
González-Zamora
Eduardo
E
Ulibarri
Gerardo
G
Negrón-Silva
Guillermo E
GE
D000812:Anhydrides / Q000138:chemical synthesis*; D001547:Benzaldehydes / Q000138:chemical synthesis*; D002384:Catalysis; D019281:Dimerization; D008872:Microwaves; D012997:Solvents / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
D000812:Anhydrides; D001547:Benzaldehydes; D012997:Solvents; D015040:Zirconium; C028541:zirconium oxide