Nanocavity microreactor containing 12- and 13-membered diaza dioxa Schiff-base copper(II) complexes have been prepared by the one-pot template synthesis of (1,8-diamino-3,6-dioxaoctane)copper(II) with bifunctional diketone within the pores of zeolite-Y. The copper(II) complexes were entrapped in the supercage of Y-zeolite by a two-step process in the liquid phase: (i) inclusion of a copper(II) precursor complex, [Cu(1,8-diamino-3,6-dioxaoctane)](2+)-NaY and (ii) template condensation of the copper(H) precursor complex with the bifunctional diketone. Encapsulated copper(II) complex is catalytically very efficient as compared to other neat complexes for oxidation of cyclohexanol with tert-butylhydroperoxide (TBHP) as oxidant and is stable to be recycled without much deterioration. (c) 2006 Elsevier B.V. All rights reserved.