Gallou, Fabrice (2025) Adding Value to Terpenes: Copper-Catalyzed Oxidation of α-Pinene in Water under Micellar Conditions. green chemistry, 27. pp. 3178-3185.

Abstract

The development of new protocols and catalytic systems for sustainable conversion of renewables such as terpenes into value-added molecules is currently in high demand. In this work, three new coordination compounds featuring mono-, di-, and tricopper(II) cores were easily assembled in aqueous ethanol medium from copper(II) nitrate, aminoalcohols, and 5-nitroisophthalic acid (H2nipa). The obtained products were formulated as [Cu(H3tea)(H2O)2](nipa)∙H2O (1), {[Cu2(μ3-dap)(μ-Hnipa)(μ3-nipa)(H2O)]∙H2O}n (2), and {[Cu3(μ3-Hmdea)2(μ4-nipa)(nipa)(H2O)3]}n (3) {H3tea, trietanolamine; Hdap, 1,3-diamino-2-propanol; H2mdea, methyldiethanolamine}. The compounds 1−3 were fully characterized, and their crystal structures disclose an ionic monocopper complex (1) and 1D coordination polymers (2, 3) with distinct secondary building units. The catalytic performance of 1−3 was evaluated under micellar aqueous-medium conditions, while studying the mild oxidation of α-pinene with tert-butyl hydroperoxide in an aqueous 1% solution of PS-750-M surfactant. Compound 1, a water-soluble complex, proved to be the most promising catalyst for the oxidation of α-pinene under micellar conditions, leading to high substrate conversion (87%) and yielding up to 54% of the main products (tert-butylperoxy-2-pinene, verbenone, and pinene oxide). Compound 2, a partially water-soluble 1D coordination polymer, also exhibits a notable catalytic behavior with the conversion of α-pinene of 87.5% and considerable total yield of the main products (44%). Apart from diversifying the types of self-assembled copper(II) cores with distinct nuclearity 4 and structural features, this work also opened up the use of such copper derivatives in the area of micellar catalysis toward the transformation of terpenes into value-added products.

Item Type:	Article
Date Deposited:	29 Apr 2025 00:45
Last Modified:	29 Apr 2025 00:45
URI:	https://oak.novartis.com/id/eprint/56104