The Reduction of Sterically Hindered <i>o</i>‐Quinone and <i>o</i>‐Iminoquinone with Gallium and “GaI”

Abstract

Abstract Metallic gallium reacts with 3,6‐di‐ tert ‐butyl‐ o ‐benzoquinone ( 3,6‐Q ) in THF to produce a gallium tris‐ o ‐semiquinolate complex, whereas the same interaction with 4,6‐di‐ tert ‐butyl‐ N ‐(2,6‐diisopropylphenyl)‐ o ‐iminobenzoquinone ( imQ ) does not proceed. The reduction of imQ is possible with amalgamed gallium in THF and produces a gallium complex that contains two o ‐iminobenzoquinone ligands in different redox states. In the case of 3,6‐Q , the analogous reaction leads to dimeric derivative [Cat 2 Ga(Et 2 O) 2 ][CatGa] (in which Cat is the dianion of 3,6‐Q ). The structure of this compound was determined by X‐ray diffraction analysis. The gallium(III) amidophenolate derivative can only be obtained by exchange reaction of APNa 2 with GaI 3 (in which AP is the dianion of imQ ). The reduction of 3,6‐Q and imQ with “GaI” results in the formation of corresponding compounds that contain redox‐active ligands in the dianionic state. The structure of [AP 2 Ga][GaI 2 ] was determined by X‐ray diffraction analysis.