A new electrochemical procedure for the synthesis of organic carbamates from amines and carbon dioxide has been developed using selective cathodic reduction of carbon dioxide in CO2-saturated room-temperature ionic liquid BMIm-BF4 solutions containing amines 1a-j, followed by addition of EtI as an alkylating agent. The synthesis was carried out under mild (PCO2 = 1.0 atm, t = 55 degrees C) and safe conditions, and the use of volatile and toxic solvents and catalysts (according to the growing demand for ecofriendly synthetic methodologies), as well as of any supporting electrolyte (for a very easy workup of the reaction mixture), was avoided. Carbamates 2a-j were isolated in good to high yields.

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A new carboxylating reagent ((-)CH(2)CN/CO(2)) was obtained by bubbling CO(2) in a CH(3)CN-TEAP (tetraethylammonium perchlorate) solution previously electrolyzed under galvanostatic control. Organic carbamates were isolated from these solutions after addition of amines and an alkylating agent. In this paper, we describe the optimized conditions for the electrochemical synthesis of carbamates from amines and CO(2), in mild and safe conditions, without any addition of bases, probases, or catalysts. Carbamates were isolated from primary and secondary aliphatic amines in high to excellent yields and from aromatic amines in moderate yields (dependent on the nucleophilicity of the nitrogen atom).

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The umpolung reaction of α,β-unsaturated aldehydes to saturated esters has been carried out in an ionic liquid by organocatalysis of electrogenerated NHC. The roles of solvent, precatalyst and proton donor of the ionic liquid have been verified and good to high yields of esters have been obtained using a "green" and mild methodology.

The electrochemical reduction of imidazolium‐based ionic liquids (BMIm‐X) leads to the formation of corresponding N‐heterocyclic carbenes (NHCs). Owing to the peculiar reactivity of NHCs, solutions containing NHC in ionic liquid (IL) can be used in CO2 capture or in organocatalyzed reactions. It is thus important to know the stability of the carbene in the parent IL. In fact, the NHC lifetime can be influenced by the nature of the anion (X−) of the IL. To better understand the relationship between NHC lifetime (and reactivity towards CO2) and IL medium, the presence of electrogenerated NHC in the parent IL is studied by using voltammetric, infrared, and thermogravimetric analyses and by isolation of the adduct between NHC and benzaldehyde. It is thus possible to estimate the actual NHC concentration and its lifetime through voltammetric peak‐current measurements. Moreover, NHC in BMIm‐X is able to catch CO2 (yielding the adduct NHC–CO2) and, triggered by heating (60‐150 °C), to release CO2. It is proven that the half‐life of NHC and the rate of CO2 capture are both affected by the nature of X−.

Cyclic voltammetry measurements provide the first direct evidence of N-heterocyclic carbene in neat 1-butyl-3-methylimidazolium acetate ionic liquid at temperatures over 120 °C.

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