Hydrogenation of ethylene carbonate catalyzed by lutidine-bridged N-heterocyclic carbene ligands and ruthenium precursors

Manganese Catalyzed Hydrogenation of Organic Carbonates to Methanol and Alcohols

“…[4] Af ew years ago,w ereported the first catalytic hydrogenation of organic carbonates and carbamates,w hich are readily available from CO 2 ,t om ethanol and alcohols using ruthenium pincer catalysts,t hus providing am ild, low pressure two-step process for the conversion of CO 2 to methanol. [8] For cost effective production and availability,c atalysts based on earth abundant metals are desirable. [6] Ding also reported ruthenium catalyzed hydrogenation of cyclic carbonates to methanol and diols.…”

“…Under the same catalytic conditions,hydrogenation of diethyl carbonate resulted in the formation of ethanol and methanol in 97 %a nd 95 %y ields,r espectively.D ibenzyl carbonate, diphenyl carbonate,a nd unsymmetrical methyl carbonates ( Table 1, entries [5][6][7][8][9][10][11] were also hydrogenated to afford the corresponding alcohol and methanol in good to excellent yields.W ethen used complex 1 for the hydrogenation of the more challenging cyclic carbonates.U nder the optimized conditions used for the hydrogenation of acyclic carbonates, only 60 %c onversion of propylene carbonate was observed, forming propylene glycol and methanol in % 60 %a nd 45 % yields,r espectively.I ncreasing the hydrogen pressure to 50 bar and reaction time to 48 hr esulted in the quantitative conversion of propylene carbonate to propylene glycol and methanol. Increasing the reaction time to 30 hand the amount of base to 4mol %resulted in approximately quantitative conversion of dimethyl carbonate to methanol, which was detected in 90 % yield by 1 HNMR spectroscopy.Encouraged by this result, we explored the hydrogenation of other types of carbonates.…”

An efficient and stable Cu/SiO 2 catalyst for the syntheses of ethylene glycol and methanol via chemoselective hydrogenation of ethylene carbonate

“…The hydrogenation of EC can be effectively catalyzed via Ru(II)-PNP complexes as a homogeneous catalyst [16]. Afterwards, Ru(II)-NHC complexes were also reported, and they showed efficient catalytic performance [17]. In terms of the easy catalyst recovery, increasing attention is given to effective heterogeneous catalyst.…”

Manganese Catalyzed Hydrogenation of Organic Carbonates to Methanol and Alcohols

“…[7] Theprocess can be viewed as am odified Omega process in which an epoxide reacts with CO 2 to form ac yclic carbonate,w hich is hydrogenated to form ethylene glycol and methanol instead of ethylene glycol and CO 2 .D espite the significance of this reaction, reports of hydrogenation of organic carbonates using homogeneous catalysts are limited to ruthenium. [8] For cost effective production and availability,c atalysts based on earth abundant metals are desirable.…”

“…Increasing the reaction time to 30 hand the amount of base to 4mol %resulted in approximately quantitative conversion of dimethyl carbonate to methanol, which was detected in 90 % yield by 1 HNMR spectroscopy.Encouraged by this result, we explored the hydrogenation of other types of carbonates. Under the same catalytic conditions,hydrogenation of diethyl carbonate resulted in the formation of ethanol and methanol in 97 %a nd 95 %y ields,r espectively.D ibenzyl carbonate, diphenyl carbonate,a nd unsymmetrical methyl carbonates ( Table 1, entries [5][6][7][8][9][10][11] were also hydrogenated to afford the corresponding alcohol and methanol in good to excellent yields.W ethen used complex 1 for the hydrogenation of the more challenging cyclic carbonates.U nder the optimized conditions used for the hydrogenation of acyclic carbonates, only 60 %c onversion of propylene carbonate was observed, forming propylene glycol and methanol in % 60 %a nd 45 % yields,r espectively.I ncreasing the hydrogen pressure to 50 bar and reaction time to 48 hr esulted in the quantitative conversion of propylene carbonate to propylene glycol and methanol. Ethylene carbonate and styrene carbonate were also successfully hydrogenated under the optimized catalytic conditions to afford the corresponding diols and methanol in approximately quantitative yields.…”