A Novel Dopamine‐Based Boronate Esters with the Organic Base as Highly Efficient, Stable, and Green Catalysts for the Conversion of CO₂ with Epoxides to Cyclic Carbonates

Abstract

A series of dopamine‐based mono‐ and dinuclear boronate esters are studied as stable, efficient, and green metal‐free catalysts for coupling CO2 with epoxides under suitable and solvent‐free conditions. Under the optimized reaction conditions, dinuclear boronate esters compared with those with mononuclear compounds display high catalytic activity and selectivity for the chemical conversion of CO2 into cyclic organic carbonates as a valuable product. Ferrocene group containing boronate ester (B4a) display the highest activity for the carboxylation of epichlorohydrin at 100 °C and 1.6 MPa of CO2 pressure, obtaining 96.3% conversion after just 2 h. After seeing a high catalytic performance of trigonal‐planar boronate ester (B1–B5) and tetrahedral boronate ester (B1a–B5a) catalysts, the effect of ionic liquid, epoxide, base, temperature, CO2 pressure, reaction time, and amount of catalyst/substrate/cocatalyst is investigated for these catalysts. The newly synthesized dopamine‐based trigonal‐planar and tetrahedral boronate esters are entirely characterized by melting point, elemental analysis, NMR (1H, 13C, and 11B NMR) spectroscopy, FT‐IR spectroscopy, UV–vis spectroscopy, and LC–MS/MS spectrometry.

Formation of Value-Added Cyclic Carbonates by Coupling of Epoxides and CO2by Ruthenium Pincer Hydrazone Complexes under Atmospheric Pressure

“…In addition, some review articles on CO 2 /epoxide coupling reactions by Kleij et al and D'Elia et al have been reported. 27,28 Furthermore, some active organo-catalysts 19,29−31 including boronate esters 32,33 and homogeneous metal complexes fabricated on various ligands like salen 34 and supported surfaces like silica 35,36 and metal centers such as cobalt, 37−47 uninuclear and binuclear aluminum, 48−52 zinc, 53,54 chromium, 55,56 iron, 57,58 tin, 59 silver, 60 scandium and yttrium, 61 and vanadium 62−64 are reported. Among the reported metal complexes, few ruthenium(II) complexes supported by wellknown ligand systems like salen 65 and porphyrin 66 have been studied for the CO 2 /epoxide coupling reaction.…”

“…Over the past two decades, various active heterogeneous catalytic systems, including metal oxides, metal carbonates, metal halides, − molecular sieves, metal-organic frameworks, − and functionalized polymers, , have been described for the CO 2 cycloaddition to epoxides. In addition, some review articles on CO 2 /epoxide coupling reactions by Kleij et al and D’Elia et al have been reported. , Furthermore, some active organo-catalysts ,− including boronate esters , and homogeneous metal complexes fabricated on various ligands like salen and supported surfaces like silica , and metal centers such as cobalt, − uninuclear and binuclear aluminum, − zinc, , chromium, , iron, , tin, silver, scandium and yttrium, and vanadium − are reported. Among the reported metal complexes, few ruthenium­(II) complexes supported by well-known ligand systems like salen and porphyrin have been studied for the CO 2 /epoxide coupling reaction.…”

Pillar-Layered Porous Metal–Organic Frameworks with Co2N2O8 Clusters and Tetragonal Ligands for CO2 Conversion

“…Renewable energy drives electrochemical CO 2 reduction reaction (CO 2 RR), enabling not only the clean and efficient synthesis of fine chemicals and fuels but also their potential for sustainable production . From the perspective of green chemistry, the chemical conversion of CO 2 and epoxides to cyclic carbonates is considered to be one of the most useful and potential methods to reduce and utilize CO 2 in practical applications. − Researchers have synthesized various materials as catalysts to accelerate the conversion of CO 2 and thereby achieve the purpose of carbon reduction, such as ionic liquids, , polymers, , zeolites, heterojunctions, , metal oxides, etc. The development of low-cost and earth-abundant transition-metal materials, such as Co, Ni, and Cu, have been widely investigated in the CO 2 conversion process during the recent years.…”

Catalysis Conversion of Carbon Dioxide and Epoxides by Tetrahydroxydiboron To Prepare Cyclic Carbonates

“…Recently, Ke et al 41 described a triethanolamine borate (TEOAB)-TBAB binary system for the preparation of cyclic carbonates at 120 °C and 1.7 MPa of CO 2 pressure (Table 1, entry 5). Kilic et al synthesized a series of N-heterocyclic carbene (NHC)-boronate ester 51 and dopamine-based boronate ester 52 catalysts for the cycloaddition reactions of CO 2 and epoxides, respectively, demonstrating high catalytic activity (Table 1, entries 6 and 7). Darensbourg, Bhat, and co-workers 53 reported a series of bifunctional organoboron-phosphonium catalysts for coupling reactions of CO 2 and epoxides, and achieved high yields of the desired products (Table 1, entry 8).…”