Regiospecific Functionalization of Azacalixaromatics through Copper-Mediated Aryl C–H Activation and C–O Bond Formation

Abstract

Regiospecific functionalization of tetraazacalix[1]arene[3]pyridines at the lower rim position of the benzene ring was achieved conveniently from their cross-coupling reaction with both aliphatic alcohols including chiral primary and secondary alcohols and phenol derivatives through the Cu(ClO(4))(2)-mediated aerobic aryl C-H activation, which gave structurally well-defined aryl-Cu(III) intermediates and a subsequent C-O bond formation reaction under very mild conditions.

Aerobic Copper-Catalyzed Organic Reactions

“…Similarly, Wang has reported similar reactivity of a copper(III) complexes of azacalixaromatics using a variety of nucleophiles including halide, cyanide, thiocyanide, carboxylate, alkoxide, and phenoxide (Scheme 122). 274 …”

Copper-catalyzed direct acyloxylation of C(sp2)-H bonds with Benzoic acids

“…On the basis of the experiments above and previous work on copper-catalyzed C-H functionalized [21][22][23][24][25], the reaction mechanism was tentatively proposed as shown in disproportion or oxidation to afford the C,N,N-Cu(III) species B. Finally, ligand exchange and reductive elimination from intermediate C delivered the desired product 2 with Cu(I).…”

Macrocyclic Aryl–Nickel(II) Complexes: Synthesis, Structure, and Reactivity Studies

“…With reference to our previously reported C−O coupling reaction of the aryl−Cu(III) analogue of 2, 17 ably, when the typical ionic compound potassium hydroxyl was employed in a mixed solvent of dimethyl sulfoxide (DMSO) and water, a good yield (82%) for the formation of hydroxylsubstituted compound 10 was achieved. Therein water is prerequisite for this reaction.…”