Alcohol amine-catalyzed CO2 conversion for the synthesis of quinazoline-2,4-(1H,3H)-dione in water

Tuning Ionic Liquid-Based Catalysts for CO2 Conversion into Quinazoline-2,4(1H,3H)-diones

Carbon capture and storage (CCS) and carbon capture and utilization (CCU) are two kinds of strategies to reduce the CO₂ concentration in the atmosphere, which is emitted from the burning of fossil fuels and leads to the greenhouse effect. With the unique properties of ionic liquids (ILs), such as low vapor pressures, tunable structures, high solubilities, and high thermal and chemical stabilities, they could be used as solvents and catalysts for CO₂ capture and conversion into value-added chemicals. In this critical review, we mainly focus our attention on the tuning IL-based catalysts for CO₂ conversion into quinazoline-2,4(1H,3H)-diones from o-aminobenzonitriles during this decade (2012~2022). Due to the importance of basicity and nucleophilicity of catalysts, kinds of ILs with basic anions such as [OH], carboxylates, aprotic heterocyclic anions, etc., for conversion CO₂ and o-aminobenzonitriles into quinazoline-2,4(1H,3H)-diones via different catalytic mechanisms, including amino preferential activation, CO₂ preferential activation, and simultaneous amino and CO₂ activation, are investigated systematically. Finally, future directions and prospects for CO₂ conversion by IL-based catalysts are outlined. This review is benefit for academic researchers to obtain an overall understanding of the synthesis of quinazoline-2,4(1H,3H)-diones from CO₂ and o-aminobenzonitriles by IL-based catalysts. This work will also open a door to develop novel IL-based catalysts for the conversion of other acid gases such as SO₂ and H₂S.

Metal-Free N-H/C-H Carbonylation by Phenyl Isocyanate: Divergent Synthesis of Six-Membered N-Heterocycles

We disclose a method using phenyl isocyanate to synthesize carbonyl-containing N-heterocycles. The metal-free novel approach for both N-H and C-H carbonylation processes was successfully refined, delivering a range of synthetically valuable derivatives of quinazoline-2,4(1H,3H)-dione, 2H-benzo[e] [1,2,4] thiadiazin-3(4H)-one 1,1-dioxide, and pyrrolo[1,2-a] quinoxalin-4(5H)-one. The protocol features broad substrates with diverse reactions suitable for excellent yields, mild conditions, and good functional group compatibility. Moreover, the applicability of the reaction was characterized by gram-scale synthesis and synthetic transformations for drug molecules.

Pyrazolone-type compounds: synthesis and in silico assessment of antiviral potential against key viral proteins of SARS-CoV-2

Coronavirus outbreak is still a major public health concern. The high mutation ability of SARS-CoV-2 periodically delivers more transmissible and dangerous variants. Hence, the necessity for an efficient and inexpensive antiviral agent is urgent. In this work, pyrazolone-type compounds were synthesised, characterised using spectroscopic methods and theoretical tools, and evaluated in silico against proteins of SARS-CoV-2 responsible for host cell entry and reproduction processes, i.e., spike protein (S), M^pro, and PL_pro. Five of twenty compounds are newly synthesised. In addition, the crystal structure of a pyrazolone derivative bearing a vanillin moiety is determined. The obtained in silico results indicate a more favourable binding affinity of pyrazolone analogues towards M^pro, and PL_pro in comparison to drugs lopinavir, remdesivir, chloroquine, and favipiravir, while in the case of S protein only lopinavir exerted higher binding affinity. Also, the investigations were performed on ACE2 and the spike RBD-ACE2 complex. The obtained results for these proteins suggest that selected compounds could express antiviral properties by blocking the binding to the host cell and viral spreading, also. Moreover, several derivatives expressed multitarget antiviral action, blocking both binding and reproduction processes. Additionally, in silico ADME/T calculations predicted favourable features of the synthesised compounds, i.e., drug-likeness, oral bioavailability, as well as good pharmacokinetic parameters related to absorption, metabolism, and toxicity. The obtained results imply the great potential of synthesised pyrazolones as multitarget agents against SARS-CoV-2 and represent a valuable background for further in vitro investigations.

Coronavirus outbreak is still a major public health concern.

Identifying the preferential pathways of CO2 capture and hydrogenation to methanol over an Mn(I)-PNP catalyst: a computational study

CO2 hydrogenation to CH3OH is a crucial conversion for several purposes. Density functional theory (DFT) studies have been performed to explore the mechanistic pathways of newly reported CO2 capture and hydrogenation to methanol. The present study describes the multistep transformation of CO2 to methanol. In this case we have introduced 2-amino-1-propanol to capture CO2 and hydrogenation of the CO2 captured product (oxazolidinone) in the presence of an active Mn(i)-PNP based catalyst. All the plausible pathways for oxazolidinone hydrogenation to methanol have been explored in detail. Here, hydride and proton transfer steps are very important for oxazolidinone hydrogenation, whereas heterolytic H2 cleavage is the most important step for the regeneration of the catalyst. Our detailed study shows that C-N bond hydrogenation followed by C-O and C[double bond, length as m-dash]O bond hydrogenations or C-O bond hydrogenation followed by C-N and C[double bond, length as m-dash]O bond hydrogenations are the most favourable pathways for oxazolidinone hydrogenation to methanol with a total reaction free energy barrier of 36.9 kcal mol-1 for both the pathways in the presence of a Mn(i)-PNP catalyst.