Bis(acetylacetonato)copper(II) catalyzed oxidative cross-dehydrogenative coupling (CDC) for the synthesis of a-acyloxy ethers through direct activation of a-C(sp Cross-dehydrogenative coupling Tertiary-butylhydroperoxide (TBHP) C–O bond formation a b s t r a c t A bis(acetylacetonato)copper(II)catalyzed convenient protocol has been developed for the synthesis of a-acyloxy ethers via cross-dehydrogenative coupling (CDC) using tertiary-butylhydroperoxide (TBHP) as the oxidant. A radical mechanism is suggested for the reaction. Transition metal catalyzed formation of the C–C and C–O bonds via functionalization of ubiquitous C–H bond has opened a new avenue of research in organic synthesis. 1 Although various strategies have been developed for the functionalization of the inert C–H bond, still cross dehydrogenative coupling (CDC) attract special attention because it is atom economic and requires no pre-functionalization of the substrate. 2 The CDC reactions have been widely employed for the C–C and C–O bond formations. 3 Due to wide applicability of C–O bond forming reactions in organic synthesis, various transition metal catalysts have been developed for the formation of C–O bond through activation of a-C(sp 3)–H bond. 4 Such activation of a-C(sp 3)–H bond adjacent to a heteroatom has become an important method for the synthesis of diverse biologically relevant structures. 5 A variety of metal catalyzed cross dehydrogenative coupling (CDC) methodologies have been developed for the oxidative activation of the C(sp 3)–H bond adjacent to a hetero atom. 6 During the past few years, a number of C–C bond forming reactions have been reported where the CDC reactions were employed for the functionalization of the C–H bond. 7 Chang's group has recently reported copper catalyzed oxidative C–H activation of formamide in the presence of sensitive carbonyl group for the formation of C–O bond. 8 a-Acyloxyethers are an important class of organic compounds and often appear as vital structural units of various biologically active compounds like artemisinin. 9 Traditional methods for their synthesis mainly rely upon the addition of carboxylic acid to the alkenyl ethers, esterification of hemiacetals 10 and the nucleophilic attack of carboxylic acid to a-halo ethers. 11 Wan et al. have reported Bu 4 NI to be an efficient catalyst for the synthesis of such a-acyloxy ethers. 12 Copper(II)oxide nano powder was reported to be a suitable catalyst for the CDC reaction of carboxylic acid to amides and a-acyloxy ethers. 13 However, on the other hand, copper(II)oxide may also catalyze the decarboxylation of acid resulting in the formation of C–C bond instead of C–O bond. 14 Herein, we report a simple yet efficient method for the construction of a-acyloxy ethers by using Cu(acac) 2 as the catalyst