Triphenylantimony(V) Catecholates Based on o-Quinones, Derivatives of Benzo[b][1,4]-Dioxines and Benzo[b][1,4]-Dioxepines

Abstract

New catecholate complexes of triphenylantimony(V), (Etgly-3,6-DBCat)SbPh₃ (I), (Propgly-3,6-DBCat)SbPh₃ (II), and (Cat-3,6-DBCat)SbPh₃ (III), based on analogs of sterically hindered 3,6-di-tert-butyl-o-benzoquinone, 5,8-di-tert-butyl-2,3-dihydrobenzo[b][1,4]dioxine-6,7-dione (L¹), 6,9-di-tert-butyl-2,3-dihydrobenzo[b][1,4]dioxepine-7,8-dione (L²), and 1,4-di-tert-butyl-dibenzo[b,e][1,4]dioxine-2,3-dione (L³), which are the 2,3-dihydrobenzo[b][1,4]dioxine, 2,3-dihydrobenzo[b][1,4]dioxepine, and dibenzo[1,4]dioxine derivatives, respectively, have been synthesized. At room temperature catecholates I and II react with molecular oxygen adding an O₂ molecule to form the corresponding spiroendoperoxides IV and V. Catecholate III reacts with oxygen with the deep oxidation of the complex and formation of neutral o-benzoquinone. The molecular structures of complexes I and III are determined by X-ray diffraction analysis (CIF files CCDC nos. 1840299 (I · toluene) and 1840300 (III)).