Iodobenzene diacetate as an efficient terminal oxidant in iron(III) porphyrin complex-catalyzed oxygenation reactions

Enhanced iron(III) corrole-catalyzed oxidations with iodobenzene diacetate: Synthetic and mechanistic investigations

“…In this work, we found that the addition of some water gives clear accelerating effect, similar to previously reported iron(III)-porphyrin catalyzed oxidations which has been ascribed to the formation of PhIO from PhI(OAc) 2 and water [27]. So most likely this is also operative with the iron(III) corrole catalyst.…”

“…1 depicts the time courses for the epoxidation in the presence and absence of water. Similar water accelerating effect observed in the reported iron(III) porphyrin-catalyzed oxidations was rationalized in terms of the formation of more oxidizing PhIO [27]. Remarkably, the catalyst loading can be as low as of 0.05 mol% (entry 4) without significant loss of activity, illustrating an unequivocally the high efficiency (1400 TON).…”

“…For example, epoxidation of cyclohexene was completed within 10 min, giving primarily epoxide with negligible amounts of allylic oxidation products (entry 2). Remarkably, Fe III (TPFC) performs as well as one of the best porphyrin catalysts known Fe III (TPFPP)Cl (TPFPP = tetrakis(pentafluorophenyl)porphinato) with respect to the epoxidation of cyclohexene under similar reaction conditions [27]. This catalytic activity (TOF) and product selectivity is a major improvement over previously reported metallocorrole catalysts [13,16] including perhalogenated Mn III (F 8 TPFC) [20] and Mn III (Br 8 TPFC) [19].…”

“…PhI(OAc) 2 , which is readily soluble in organic media and safe to use, has been less often employed due to its mild oxidizing ability. Collman and Nam reported, respectively, the use of PhI(OAc) 2 as terminal oxidant for the iron(III) porphyrin catalyzed oxidation of hydrocarbons [26,27]. Adam et al also described a highly selective oxidation of alcohols by chromium(III) salen with PhI(OAc) 2 [28].…”

Biomimetic alkane oxidation by iodosylbenzene and iodobenzene diacetate catalyzed by a new manganese porphyrin: Water effect

“…A theoretical study by Barcelles et al [14] has shown that water may act as an axial ligand. On the other hand, In et al [15] have reported that water hydrolyzes PhI(OAc) 2 , to generate PhIO in situ. Silva et al [16] have verified that water enhances catalyst efficiency during cyclohexane oxidation by PhIO and PhI(OAc) 2 , whereas CarvalhoDa-Silva et al [17] have not detected any rise in product yield upon addition of water to systems that employ PhIO as oxidant.…”