摘要
Three new copper(II)compounds,formulated as[Cu(pdc)(H_(3)tea)(H_(2)O)](1),[Cu_(2)(μ_(3)-pdc)_(2)(DMF)(H_(2)O)_(2)]n·2nH_(2)O(2)and[Cu_(2)(μ4-pdc)_(2)(H_(2)O)_(3)]n·3nH_(2)O(3),were generated from copper(II)nitrate,3,4-pyridinedicarboxylic acid(H_(2)pdc),and triethanolamine(H_(3)tea).Their crystal structures revealed a discrete 0D complex(1)as well as 2D(2)and 3D(3)coordination polymers(CPs).The obtained compounds were screened as precatalysts for the oxidation of terpenes with molecular oxygen as the oxidizing agent and t-BuOOH as the radical initiator.The relationship between the precatalyst structures and the accumulation ofα-pinene oxidation products was investigated.Among the three compounds,compound 2 revealed the best activity inα-pinene oxidation.Under the optimized conditions,the conversion ofα-pinene reached∼90%,yielding pinene oxide,verbenyl hydroperoxide,verbenol,and verbenone as the main products.Furthermore,compound 2 can catalyze the oxidation of(+)-valencene with O2 to give(+)-nootkatone.This study showcases the successful synthesis of three new copper-pyridinedicarboxylate derivatives,among which the 2D coordination polymer 2 acts as a particularly efficient precatalyst for upgrading terpenes into value-added oxyfunctionalized products.
基金
funding from the EU via its Horizon 2020 research and innovation programme under Grant Agreement No.860762(CHAIR project)
the Foundation for Science and Technology(FCT,Portugal,PTDC/QUI-QIN/3898/2020,UIDB/00100/2020,UIDP/00100/2020,LA/P/0056/2020,and UID/00100/2023)
the research contracts within the PTDC/QUI-QIN/29697/2017 and PTDC/QUI-QIN/3898/2020 projects(2021-2024).
