Iron‐Catalyzed Synthesis of Five‐Membered Cyclic Carbonates from Vicinal Diols: Urea as Sustainable Carbonylation Agent

Abstract

A new iron‐catalyzed synthesis of cyclic carbonates from the corresponding vicinal diols and urea is described. This straightforward transformation allows for the preparation of a variety of five‐membered carbonates by employing an inexpensive and environmentally benign iron salt as the catalyst. The use of readily available feedstocks such as urea and polyols makes this a sustainable process. As ammonia is formed as the only stoichiometric byproduct, this process can also be characterized by its high atom economy.

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

“…They are found in various natural and potential pharmaceutical products [ 15 ]. Moreover, they are used as electrolyte components in Li-ion rechargeable cells and as aprotic polar solvent with high boiling point as alternative of dangerous solvents because of their good biodegradability and low toxicity [ 16 – 18 ]. Synthetic intermediates for ring-opening polymerization of the compounds containing cyclic carbonates such as methyl 4,6- O -benzylidene-2,3- O -carbonyl-α-ᴅ-glucopyranoside (MBCG) ( 5 ) [ 19 – 20 ] and glycerol carbonate ( 6) [ 21 ] were also reported ( Scheme 1 ).…”

One-Pot Synthesis of Oxazolidinones and Five-Membered Cyclic Carbonates from Epoxides and Chlorosulfonyl isocyanate: Theoretical Evidence for the Asynchronous Concerted Pathway

“…They are found in various natural and potential pharmaceutical products [15]. Moreover, they are used as electrolyte components in Li-ion re-chargeable cells and as aprotic polar solvent with high boiling point as alternative of dangerous solvents because of their good biodegradability and low toxicity [16][17][18]. Synthetic intermediates for ring-opening polymerization of the compounds containing cyclic carbonates such as methyl 4,6-O-benzylidene-2,3-O-carbonyl-α-D-glucopyranoside (MBCG) (5) [19][20] and glycerol carbonate (6) [21] were also reported ( Figure 1).…”

“…The most wellknown strategies for the synthesis of oxazolidinones are the reaction of an amino alcohol with phosgene [5,22], carbonylation reaction of β-amino alcohols with CO2 or dialkyl carbonates [23][24][25][26][27], multicomponent reaction by rare-earth metal amides [28], reaction of CO2 with propargylamines or aziridines [29,30] and cycloaddition reaction of epoxides with isocyanates [31,32]. On the other hand, for synthesis of five membered cyclic carbonates, the cycloaddition of CO2 to epoxides, the reaction with the metal complexes or catalysts, and the reaction of a diol with toxic phosgene are the most common processes [16,17,[33][34][35][36].…”

Iron‐Catalyzed Reaction of Urea with Alcohols and Amines: A Safe Alternative for the Synthesis of Primary Carbamates

“…Initially,w es tudied the reaction of urea (1)w ith 1-undecanol (2a)a samodel system.T oo ur delight, the treatment of 0.5 mmol of 1 with 3equivalents of 2a in the presence of 4mol %o fF eBr 2 in tert-amyl alcohol at 150 8Cf or 18 hp rovided undecyl carbamate (3a)s electively in ag ood 76 %y ield (Table 1, entry 1). [17] Despite the excess of alcohol used, the nucleophilic substitution on ureao nly takes place once, so the formation of the corresponding acyclic carbonate is completely avoided. [18] Next, we optimizedt his reaction owing to the high selectivity observed.…”