Characterization and Reactivity of a Tetrahedral Copper(II) Alkylperoxido Complex. Issue 47 (1st August 2019)

• Record Type: Journal Article
• Authors: Shimizu, Ikuma; Morimoto, Yuma; Velmurugan, Gunasekaran; Gupta, Tulika; Paria, Sayantan; Ohta, Takehiro; Sugimoto, Hideki; Ogura, Takashi; Comba, Peter; Itoh, Shinobu
• Is Part Of: Chemistry. Volume 25:Issue 47(2019)
• Page Start: 11157
• Page End: 11165
• Publication Date: 2019-08-01
• Subjects: bioinspired compounds -- C−H activation -- copper -- O−H activation -- reaction mechanisms; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201902669
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A tetrahedral Cu II alkylperoxido complex [Cu II (TMG3 tach)(OOCm)] + (1 OOCm ) (TMG3 tach={2, 2′, 2′′‐[(1s, 3s, 5s)‐cyclohexane‐1, 3, 5‐triyl]tris‐(1, 1, 3, 3‐tetramethyl guanidine)}, OOCm=cumyl peroxide) is prepared and characterized by UV/Vis, cold‐spray ionization mass spectroscopy (CSI‐MS), resonance Raman, and EPR spectroscopic methods. Product analysis of the self‐decomposition reaction of1 OOCm in acetonitrile (MeCN) indicates that the reaction involves O−O bond homolytic cleavage of the peroxide moiety with concomitant C−H bond activation of the solvent molecule. When an external substrate such as 1, 4‐cyclohexadiene (CHD) is added, the O−O bond homolysis leads to C−H activation of the substrate. Furthermore, the reaction of1 OOCm with 2, 6‐di‐ tert ‐butylphenol derivatives produces the corresponding phenoxyl radical species (ArO . ) together with a Cu I complex through a concerted proton‐electron transfer (CPET) mechanism. Details of the reaction mechanisms are explored by DFT calculations. Abstract : Double action : A Cu II alkylperoxido complex exhibiting an unusual tetrahedral geometry has been prepared and characterized by several spectroscopic methods. The complex exhibits C−H and O−H bond activation reactivity towards 1, 4‐cyclohexadiene and phenol derivatives (see scheme). Mechanistic details are explored by kinetic analysis and DFT calculations, providing important insights into the reactivity of the bioinspired Cu II peroxido complex.