DBU and DBU‐Derived Ionic Liquid Synergistic Catalysts for the Conversion of Carbon Dioxide/Carbon Disulfide to 3‐Aryl‐2‐oxazolidinones/[1,3]Dithiolan‐2‐ylidenephenyl‐ amine

Abstract

An intermolecular synergistic catalytic combination of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) and a DBU‐derived bromide ionic liquid has been developed for the conversion of CO2, epoxides, and amines under metal‐ and solvent‐free conditions. Various 3‐aryl‐2‐oxazolidinones are produced in moderate to excellent yields within a short reaction time. NMR spectroscopy and DFT calculations demonstrate that DBU as a hydrogen bond acceptor and the ionic liquid as a hydrogen bond donor activate the substrates cooperatively by inducing hydrogen bonds to promote the reaction effectively. Based on these results, a possible reaction mechanism on the synergistic catalysis of DBU and the ionic liquid is proposed. In addition, the reaction of CS2, ethylene oxide, and aniline catalyzed by the combination of DBU and the DBU‐derived ionic liquid also proceeds smoothly, which opens a hitherto unreported route to [1,3]dithiolan‐2‐ylidenephenylamine in a straightforward way.

Cocatalyst‐Free Hybrid Ionic Liquid (IL)‐Based Porous Materials for Efficient Synthesis of Cyclic Carbonates through a Cooperative Activation Pathway

“…[2][3][4] Differentt ypes of CO 2 conversion processes have been examined, among which the cycloaddition of CO 2 with epoxides to produce aw idely applicable biodegradable cyclic carbonate is one of the most interesting processes. To date, aw ide range of homogeneous and heterogeneous catalysts have been developed, such as alkali-metal salts, [7] metal oxides, [8] organophosphorus compounds, [9] organic bases, [10] organometallic compounds, [11] functional polymers, [12] andi onicl iquids( ILs). [5,6] The synthesis of cyclic carbonates can be traced back to more than four decades ago.…”

“…[5,6] The synthesis of cyclic carbonates can be traced back to more than four decades ago. To date, aw ide range of homogeneous and heterogeneous catalysts have been developed, such as alkali-metal salts, [7] metal oxides, [8] organophosphorus compounds, [9] organic bases, [10] organometallic compounds, [11] functional polymers, [12] andi onicl iquids( ILs). [13] In view of green chemistry and sustainability,m etal-free catalysts are more desirable.…”

Synthesis of Oxazolidinones and Derivatives through Three‐Component Fixation of Carbon Dioxide

“…3‐(3‐chlorophenyl)‐5‐methyloxazolidin‐2‐one ( 42 a ): White oil. 1 H NMR (400 MHz, CDCl 3 ): δ =7.56 (t, J= 2.0 Hz, 1 H), 7.47–7.44 (m, 1 H), 7.29 (t, J= 8.0 Hz, 1 H), 7.12–7.09 (m, 1 H), 4.83–4.78 (m, 1 H), 4.10 (t, J= 4.4 Hz, 1 H), 3.61 (t, J= 7.2 Hz, 1 H), 1.54 ppm (t, J= 6.0 Hz, 3 H).…”

“…Recently, a few three‐component reactions to prepare oxazolidinones from CO 2 have been reported (Scheme ) . The three‐component reaction of amines, ethylene oxide with CO 2 was explored mostly and amino alcohols, phenyl isocyanate and cyclic carbonates have been proposed as intermediate in the catalytic cycle . Besides, there is one report about three‐component reaction of 1,2‐dibromoethane, anilines with CO 2 .…”

Boosting the Catalytic Performance of Organic Salts for the Fast and Selective Synthesis of α‐Alkylidene Cyclic Carbonates from Carbon Dioxide and Propargylic Alcohols

“…In 2016, Wang et al. reported a series of new reusable ILs derived from 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) that were able to promote the synthesis of αCCs at 60 °C and 25 bar . Even at an ILs loading of 200 mol % compared to propargylic alcohols, the coupling reaction remained slow as attested by yields of 68–89 % after 24 h. This moderate activity might be related to the low basicity of ILs.…”