Copper(I)‐Arene Complexes with a Sterically Hindered Tris(pyrazolyl)borate Ligand. Issue 19 (17th May 2018) - Álvarez, María
Abstract : A series of arene copper(I) complexes bearing the hydrotris(3‐mesitylpyrazolyl)borate ligand (Tp Ms ) of general formula Tp Ms Cu(arene) (arene = toluene, 1 ; nitrobenzene, 2 ; chlorobenzene, 3 ; and iodobenzene, 4 ) has been structurally characterized. Complexes1 –3 show a η 2 ‐arene coordination mode to the copper center, whereas the iodobenzene ligand in4 is coordinated to Cu by the iodine atom. In the absence of excess arene, these compounds undergo arene loss and formation of the dinuclear complex [Tp Ms Cu]2 (5 ), which has also been structurally characterized. Given the number of catalytic systems described in which the Tp x Cu core plays the main role, the observation of these adducts assesses their presence in those catalytic systems, a feature not described to date. Abstract : Copper(I)‐arene complexes are generated when Tp Ms Cu(THF) is exposed to excess amounts of C6 H5 ‐R. The new compounds are unstable upon isolation, but their formation in solution is relevant in the context of Tp x Cu‐mediated catalytic transformations.