Gallou, Fabrice (2025) Copper(II) Coordination Polymers Driven by 3,4-Pyridinedicarboxylic Acid: Synthesis, Scale Up, Crystal Structures, and Catalytic Behavior in Allylic Oxidation of a-Pinene. RSC Sustainability.

Abstract

a-Pinene is one of the most abundant and low-cost terpenes that can be used as a
renewable feedstock for generating added-value oxidation products via allylic oxidation.
Aiming at the development of novel catalytic systems for the functionalization of
terpenes, in this work two new isostructural 2D coordination polymers (CPs), {[Cu2(µ-
pdc)(µ3-pdc)(H2mdea)(H2O)2].2H2O}n (Cu-mdea) and {[Cu2(µ-pdc)(µ3-
pdc)(H3tipa)(H2O)2].4H2O}n (Cu-tipa) {H2pdc = 3,4-pyridinedicarboxylic acid, H2mdea
= methyldiethanolamine and H3tipa = triisopropanolamine} were synthesized via selfassembly
method under green conditions. These compounds were fully characterized, and their crystal structures were established. The topological analysis depicted the formation of uninodal 4-connected nets with the sql topology, which are driven by the 5-coordinated copper(II) units and pdc2- linkers. Through an optimized scale-up process from milligram to gram scale, a larger quantity of pure crystalline materials (~8.0 g) was obtained with higher yields (~70%) compared to the small-scale reaction (~60%). The obtained CPs were applied as efficient and recyclable heterogeneous catalysts for the mild oxidation of a-pinene with tert-butyl hydroperoxide. The effects of various reactions parameters, temperature-dependent and mechanistic studies, and catalyst stability were investigated in detail, leading to up to 93% of a-pinene conversions with good yields of 4-tert-butylperoxy-2-pinene (42%) and verbenone (25%) as main oxidation products. This study opens up the use of copper(II) coordination polymers as promising heterogeneous catalysts for the allylic oxidation of a-pinene into value-added products.

Item Type:	Article
Date Deposited:	01 Jul 2025 00:46
Last Modified:	01 Jul 2025 00:46
URI:	https://oak.novartis.com/id/eprint/55069