Deoxydehydration of polyols catalyzed by a molybdenum dioxo-complex supported by a dianionic ONO pincer ligand

Abstract

Molybdenum cis-dioxo bis-phenolate ONO complexes were synthesized and have been shown to be active for DODH. Catalysts were screened for activity at 190 °C and ambient pressure, and appreciable alkene yields of up to 59% were obtained.

A Cp‐based Molybdenum Catalyst for the Deoxydehydration of Biomass‐derived Diols

“…The TON per Mo in these cases is 11 and 6, respectively. [18,20] In our case, the application of the Cp* ligand also gives a quite good alkene product selectivity (55 %) and TON per catalyst (27; i. e. 14 per Mo).…”

“…Very recently, Kilyanek et al reported a dioxomolybdenum complex supported by a dianionic ONO pincer ligand, which catalyzes the DODH of diols using PPh 3 , Na 2 SO 3 , Zn, C, 3-octanol or 2-propanol as reductant. [20] For these ligandsupported "MoO 2 " DODH catalysts similarly low TONs per "MoO 2 " were found as for the AHM systems; the highest TON being around 9.…”

“…[1] DODH reactions allow for high oxygen-content starting materials, such as cellulosic biomass derivatives, to be converted into useful olefins. Next to a number of heterogeneous catalysts, soluble metal complexes based on rhenium, [1][2][3][4] vanadium, [5][6][7][8][9][10][11][12][13] and molybdenum, [14][15][16][17][18][19][20][21][22][23] have been reported to catalyze the DODH of diols and polyols. In terms of activity and selectivity, rhenium complexes so far outperform homogeneous catalysts based on vanadium and molybdenum.…”

“…For the homogeneous molybdenum-catalyzed DODH of diols and polyols, a relatively limited number of examples have been reported, [24] mainly including the use of molybdate salts [15][16][17]21] or dioxo-Mo(VI) complexes. [14,[18][19][20] Ammonium heptamolybdate ((NH 4 ) 6 Mo 7 O 24 , AHM), a commercially available molybdate salt, has been reported as a catalyst for the deoxydehydration of diols. The first example was reported by Fristrup and co-workers in 2014.…”

Direct Deoxydehydration of Cyclic Trans-Diol Substrates: An Experimental and Computational Study of the Reaction Mechanism of vanadium(V)-Based Catalysis

“…5 Metal catalysts that have been successfully explored are rhenium, [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] vanadium [24][25][26][27] and molybdenum. [28][29][30][31][32][33][34][35] Rhenium has provided the most efficient and highest yielding catalysts but is the most expensive of the three metals.…”