Synthesis, Characterization, and Application of Oxo-Molybdenum(V)-Corrolato Complexes in Epoxidation Reactions

Abstract

Sharpless et al. have described, while performing the molybdenum-catalyzed epoxidation reaction of olefins using alkyl hydroperoxides, that the molybdenum-oxo moiety is an active catalytic species. Thus, continuous efforts have been made to synthesize molybdenum-oxo complexes of different ligand environments. While plenty of such works on molybdenum porphyrins are reported in the literature, related molybdenum corroles are very less reported. The synthesis and characterization of two new oxo-molybdenum­(V)-corrolato complexes are described herein. Both the complexes have been fully characterized by several spectroscopic techniques in conjunction with single-crystal X-ray diffraction analysis. The efficacy of the oxo-molybdenum­(V)-corrolato complexes for the catalytic epoxidation reaction of olefins with the help of hydroperoxides has also been explored. The catalytic application of oxo-molybdenum­(V)-corrolato complexes in the epoxidation reaction has not been reported earlier. A mechanism has been proposed to explain the experimental findings.

Oxo(corrolato)vanadium(iv) catalyzed epoxidation: oxo(peroxo)(corrolato)vanadium(v) is the true catalytic species

“…Corrole, a contracted porphyrin analog, is known to stabilize metals in a higher oxidation state. [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] Corrole has excellent chelating properties; many metal complexes across the periodic table bearing corrole ligand functionalities have already been reported in the literature. [50][51][52][53][54][55][56][57][58][59][60][61][62][63] Licoccia et al first synthesized oxo(corrolato)vanadium(IV) complexes bearing b-substitution at the corrole periphery.…”

Synthesis, Characterization, and the N Atom Transfer Reactivity of a Nitridochromium(V) Complex Stabilized by a Corrolato Ligand

“…Corroles are trianionic when fully deprotonated as opposed to porphyrin, which is dianionic . The inner π system of corrole is more electron-rich, and thus, it stabilizes the higher oxidation states of metals. − Transition metal complexes bearing multiple bonds between metals and ligands, e.g., nitrido, imido, oxo, alkylidyne, and alkylidene, have gained considerable research interest in recent times. − Multiple bonded metal–ligand complexes are frequently invoked in the atom and group transfer reactions. In this context, metal complexes bearing nitride ligands (MN) are at the forefront of current scientific research due to their resemblance with the metal complexes involved in the nitrogen fixation reactions. , Nitride complexes are also efficiently used in the nitrogenation reactions of various organic compounds. , The nitride ligand is also known for the stabilization of higher oxidation states of metals.…”

Hydrogen evolution catalysis by terminal molybdenum-oxo complexes

“…The important chemistry of molybdenum complexes remains a main motivation for investigating its chemistry within the trianionic N 4 -coordination sphere of corroles, well known to increase the activity of low valent metal ions chelated by it ( Johansen et al., 2011 ; Mody et al., 2009 ; Nayak et al., 2020 ; Sashuk et al., 2004 ). Regardless of the molybdenum source used, metalation of corroles invariably leads to isolation of robust 5-coordinated (oxo)molybdenum(V) complexes.…”