A metal-free porphyrin heterogenised onto SBA-15 silica: A performant material for the CO2 cycloaddition to epoxides and aziridines

Recent advances in the accessibility, synthetic utility, and biological applications of aziridines

“…60 A typical ring enlargement reaction concerning aziridines is the one with CO 2 (204). 61 Indeed, different methodologies were described by using diverse catalysts. 62 Among them, Caselli and co-workers reported the preparation of 5-substi- The structure was confirmed by computational calculation and X-ray studies.…”

From CO2 to CS2: a theoretical investigation of the cycloaddition to aziridines mediated by metal-free porphyrin-based catalytic systems

“…Even if the energy barrier was particularly high, the formation of 8 could reasonably occur by employing the same experimental conditions (temperatures higher than 80 1C) required for CO 2 activation. [21][22][23][24][25][26] The high temperature reasonably allows overcoming the high estimated energy barrier.…”

“…In the recent years we have investigated the catalytic activity of porphyrin-based systems in the CO 2 cycloaddition to aziridines [21][22][23][24] and the symbiotic computational/experimental approach has highlighted the high efficiency of the metal-free TPPH 2 /TBACl binary catalyst (TPP = dianion of tetraphenyl porphyrin, TBACl = tetrabutyl ammonium chloride) in promoting the synthesis of N-alkyl and N-aryl oxazolidine-2-ones under both homogenous and heterogeneous conditions. 25 DFT calculations pointed out the formation of the active adduct 1 (Scheme 1) where the butyl substituents of the TBA + cation are perfectly hosted in the crib formed by the peripheral meso substituents of the porphyrin macrocycle. Adduct 1 has been estimated to be more stable by ca.…”

Metal Hydrogen-Bonded Organic Frameworks as Open Lewis Acid Catalysts for Two Types of CO2 Transformations

“…As a primary contributor to the greenhouse effect, the rising levels of carbon dioxide (CO 2 ) in the atmosphere are causing a cascade of climate-related issues, posing a significant threat to human life and safety. − The fixation and transformation of CO 2 are regarded as crucial methods for mitigating the concentration of CO 2 in the atmosphere and achieving carbon neutrality. Given that CO 2 being a nontoxic, abundant, and recyclable C1 source, chemical technology can be employed to convert CO 2 into high-value-added chemicals, such as urea, carbonates, − oxazolidinones, − carboxylic acids, − and reductive products. − Green, efficient, and versatile CO 2 transformations hold great potential for further application. , However, many catalytic systems currently require noble metal catalysts, require high pressure, and are commonly limited to a single type of conversion. Consequently, the exploration of a noble-metal-free and efficient catalyst to realize various CO 2 transformations under mild conditions has considerable significance for CO 2 consumption and industrial production.…”