Revisiting the Mukaiyama-type epoxidation for the conversion of styrene into styrene carbonate in the presence of O₂ and CO₂

Abstract

Since its first report in the early 1990s, Mukaiyama-type aerobic epoxidation involving the presence of an aldehyde as an electron donor is considered as an interesting oxidation reaction. Among the...

Design of Simple Salophen Chromium Complexes for a Two-Steps Oxidative Carboxylation of Styrene with Co2 and O2

“…First, a unique solvent should be used. Here, benzonitrile was selected since both individual steps were previously successfully performed by us in this solvent [20], [21], [26], [27] with similar reagents/products concentrations. Here, the respective concentrations of the different reagents, i.e.…”

“…Recently, we described the oxidative carboxylation of styrene with O 2 and CO 2 using Salophen-tBu-Cr complex and n-Bu 4 NBr in the presence of isobutyraldehyde (IBA), [26] through a one-step approach with a single set of temperature and pressure parameters (see Table S2 for a reminder). The idea was to produce styrene oxide in-situ based on a Mukaiyama-type process requiring the use of a sacrificial aldehyde.…”

“…The pressure was then set at 11 bar of CO 2 and the reaction carried out again at 80°C. The delayed introduction of CO 2 , (M)Salophen and n-Bu 4 NBr was justified [26] by the fact that Salophen complexes are not mandatory during the oxidation step at 80°C (see also figure S9, Table S2, entry 1). Experimental settings for three different tests are presented in Table 2 and the corresponding results are displayed in Figure 3.…”

Investigation and Comparison of Catalytic Methods to Produce Green CO2-Containing Monomers for Polycarbonates

“…Although replacing ethylene oxide with carbon dioxide makes ecological sense, this approach has not made its way to the market so far [2][3][4]. Further catalysts and variations in the product structures are still being researched today [2,3,[5][6][7][8][9][10][11][12][13][14]. The synthesis of CO 2 -containing polymers is still very challenging, aiming at the avoidance of high-energy costs during copolymerization and extreme conditions such as high temperatures and pressures.…”

“…This results in a network for the production of modern alternative CO 2 -containing polymers such as poly(ethylene ether carbonate) from cEC or polystyrene carbonate from cyclic styrene carbonate (see Figure 2) [11,21,22,24,25]. Due to strict environmental and safety requirements regarding the hazardous nature of phosgene, the phosgenation route is not considered in this study.…”