Bifunctional Boron Phosphate as an Efficient Catalyst for Epoxide Activation to Synthesize Cyclic Carbonates with CO₂

Abstract

Development of inexpensive, easily prepared, non-toxic, and efficient catalysts for the cycloaddition of CO with epoxides to synthesize five-membered cyclic carbonates is a very attractive topic in the field of CO transformation. In this work, we conducted the first work on the cycloaddition of CO with epoxides to produce cyclic carbonates catalyzed by a binary catalyst system consisting of KI and boron phosphate (BPO ), which are both inexpensive and non-toxic, and various corresponding cyclic carbonates could be produced with high yields (93-99 %) at 110 °C with a CO pressure of 4 MPa under solvent-free conditions. In the BPO /KI catalyst system, BPO , a Brønsted and Lewis acid hybrid, played the role of activating the epoxy ring through the formation of hydrogen bonds with Brønsted acidic sites and the interaction with Lewis acidic sites simultaneously, and thus enhanced the activity of KI for the cycloaddition of CO with epoxides significantly. Additionally, the activity of the BPO /KI catalyst system showed no noticeable decrease after being reused five times, indicating that the BPO was stable under the reaction conditions.

Recent advances in catalytic conversion of carbon dioxide to propiolic acids over coinage-metal-based catalysts

“…Pioneering contributions in this area include the codimerization of isoprene with CO 2 firstly disclosed by Hoberg, and the copolymerization of epoxides with CO 2 initially reported by Inoue [10,11]. In addition, the latest progress examples include the synthesis of salicylic acid from the reaction of phenol salts with CO 2 [12][13][14], the hydrogenation of CO 2 with hydrogen to formic acid (HCO 2 H) [15][16][17][18][19][20][21][22][23][24][25][26][27], methanol [28], ethanol [29], the carboxylation of olefin with CO 2 to acrylic acids catalyzed by coinage-metal-based catalysts [30][31][32][33][34], the cycloaddition of CO 2 with epoxides to give cyclic carbonates [35][36][37][38][39][40][41][42][43], and the reaction of CO 2 with amines to afford carbamates [44][45][46][47][48][49].…”

Insights into the BPO4‐Driven Catalytic Mechanism for the Formation of Cyclic Carbonates from CO2 and Epoxides

“…Besides, it is a low‐cost catalyst. The first study on epoxides catalyzed by BPO 4 was reported by Xue et al [27] . They proposed that the BPO 4 catalyst plays a role in activating the epoxy ring by forming hydrogen bonds with Brønsted acidic sites and simultaneously interacting with Lewis acidic sites on the catalyst.…”

Efficient Solvent‐Free Carbon Dioxide Fixation Reactions with Epoxides Under Mild Conditions by Mixed‐Ligand Zinc(II) Metal–Organic Frameworks

“…However, limitations of product separation and catalyst recycling are of real concern in the homogeneous catalytic reaction. These limitations have been tackled to a great extent by the utilization of heterogeneous catalysts that include metal oxides, coordination complexes, zeolites, and functional polymers, which display a low activity under ambient conditions or leaching …”

“…CO 2 has attracted the attention of researchers in recent times as a carbon source for several organic transformations because it is an abundant, renewable, and safe C1 feedstock that is easy to handle, nonflammable, and nontoxic . Transformations of CO 2 , such as CO 2 fixation reactions with epoxides to yield five‐membered cyclic carbonates, have been well‐established with various homo‐ and heterogeneous catalysts that include metal oxides, coordination complexes, and supported ionic liquids . The green catalytic conversion of a C1 feedstock readily available from combustion into value‐added cyclic carbonates that can be applied as a raw material for cosmetics, intermediates in the synthesis of ethylene glycol, acyclic carbonates, pharmaceuticals, polymers, and as an electrolyte in batteries has been reported .…”