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Green Catalysis, Green Chemistry, and Organic Syntheses for Sustainable Development
Published in Miguel A. Esteso, Ana Cristina Faria Ribeiro, A. K. Haghi, Chemistry and Chemical Engineering for Sustainable Development, 2020
Divya Mathew, Benny Thomas, K. S. Devaky
The potential of BAILs has been exploited in many organic transformations like Beckmann rearrangement, aldol condensation, Michael reaction, and so on. Sulfonyl-containing ionic liquid can also be used as a green, solvent-free, metal-free, mild, and efficient recyclable catalyst. Acidic ionic liquids are reported to be ideal solvent for Friedel–Crafts acylation reactions. Acidic chloroaluminate ionic liquids can generate acylium ions, as the Lewis acid catalysts like AlCl3 or FeCl3 do with acyl chloride. Basic ionic liquids are found to be effective to catalyze a number of reactions like aza-Michael addition reaction, Michael addition of active methylene compounds, condensation reaction of aldehydes and ketones with hydroxylamine, and synthesis of quinolines and pyrroles. Hydrogen bonding interactions are one of the promising strategies in organocatalysis.
Atom Economy
Published in Aidé Sáenz-Galindo, Adali Oliva Castañeda-Facio, Raúl Rodríguez-Herrera, Green Chemistry and Applications, 2020
Kunnambeth M. Thulasi, Sindhu Thalappan Manikkoth, Manjacheri Kuppadakkath Ranjusha, Padinjare Veetil Salija, Nisha Vattakkoval, Shajesh Palantavida, Baiju Kizhakkekilikoodayil Vijayan
Nguyen and Retailleau in 2017, reported for the first time, a redox-neutral, catalyst free, completely atom-economical synthesis of sultams. Sultams are cyclic derivatives of sulfonamides and are used as important scaffolds in medicinal chemistry. Their uses also include antibacterial activity, lipoxygenase inhibition, drugs for heart disease, etc. Redox and non-redox approaches were widely used for the preparation of sulfonamides and sultams. In the redox method, the widely used strategy is the oxidation of sulfonamide derivatives such as sulfenylamides and sufinylamides and in non-redox method, the condensation of amines with activated sulfonyl group is utilized. In both strategies, the atom economy can never attain 100%. In the new method, elemental sulfur was used as a versatile synthetic tool in sulfonamide synthesis without any byproducts. Nguyen presented a total atom economical approach for the synthesis of sultams (Scheme 2.25) which involves heating of 2-nitrochalcones with elemental sulfur in the presence of N-methylmorpholine or 3-picoline without any catalyst.
Organic Low-Dielectric Constant Materials for Microelectronics
Published in Sam-Shajing Sun, Larry R. Dalton, Introduction to Organic Electronic and Optoelectronic Materials and Devices, 2016
Poly(arylene ethers) (PAEs) are prepared by nucleophilic reaction of halogen-activated electron deficient aromatic rings and bisphenols as shown in Figure 28.6. The polymer’s properties can be changed by modifying the chemical structure of the halogenated aromatic precursor or bisphenol. The aromatic rings in the PAE provide good mechanical and thermal properties with Tg of over 400°C [19]. The flexible ether linkages allow bending of the chains, which yield more isotropic materials than polyimides. Carbonyl and sulfonyl groups are very effective as electron-withdrawing groups to activate the aromatic rings and to drive the reaction to completion. However, because these groups are highly polar, they are typically avoided in PAE to achieve desirable low-dielectric constants. FLARE from Honeywell is one of the best-known PAE. Recently, there are reports of integrating FLARE into dual-damascene Cu structures [20]. Typical non-fluorinated PAEs have k value of 2.8–2.9, low moisture uptake, and good solvent resistance. Fluorinated versions of PAEs have k value of ~2.4.
Synthesis of novel adamantane-containing dihydropyrimidines utilizing Biginelli condensation reaction
Published in Journal of Sulfur Chemistry, 2023
Mina Abkar Aras, Adeleh Moshtaghi Zonouz
Among the diverse biological activities of DHPMs, the calcium channel blocking activity of these molecules has been more explored. Based on structure–activity relationship (SAR) studies, it has been found that in addition to 2-hetero substituent (S > O > N), 4-ortho and/or meta aromatic substitution (Cl, NO2, CF3) and 5-ester alkyl group (isopropyl > ethyl > methyl) are essential for optimal calcium channel blocking activity of DHPMs. Additionally, a substituent (alkyl, acyl, carbamate, sulfonyl, uriedo) on N3 is required for activity; DHPMs lacking a N3-substituent were found to be devoid of potency. The order of activity for N3-alkyl substituted DHPMs is methyl > ethyl > isopropyl. On the other hand, N1-alkyl substitution abolishes calcium channel inhibition (N1-H is essential) [50]. Hence it is expected the bulky lipophilic bullet adamantly at C-5 position to improve calcium channel blocking activity of this class of compounds.
A green and novel method for synthesis of β-sulfonyl esters under solvent-free conditions
Published in Journal of Sulfur Chemistry, 2021
Gholamhassan Imanzadeh, Havva Rezaei, Roghayyeh Asgharzadeh, Zahra Soltanzadeh
Sulfonyl hydrazides with general structure R–SO2–NH–NH2 (Scheme 1) can be readily prepared by treating sulfonyl chlorides with aqueous hydrazine solution [16,17]. Many methods have developed for synthesis of sulfonyl hydrazide derivatives [1,16,18–25]. In general, they exist as solids that are noncorrosive, compatible with water, and free of unpleasant odor [26]. Sulfonyl hydrazides have widespread applications in organic synthesis chemistry [27,28]. As an interesting application of sulfonyl hydrazides, they are used as sulfonyl sources in organic synthesis and the first was reported in 1961 [29]. In this application when sulfonyl hydrzide would transformed to sulfonyl anion it can utilize to form carbon–sulfur bond to afford sulfones [30,31]. Sporadic examples have shown that sulfonyl hydrazides can serve as sulfonyl sources for the preparation of sulfonamides, sulfonyl halides, thiosulfonates, and selenosulfonates [26].
A critical review on remediation of bisphenol S (BPS) contaminated water: Efficacy and mechanisms
Published in Critical Reviews in Environmental Science and Technology, 2020
Zheng Fang, Yurong Gao, Xiaolian Wu, Xiaoya Xu, Ajit K. Sarmah, Nanthi Bolan, Bin Gao, Sabry M. Shaheen, Jörg Rinklebe, Yong Sik Ok, Song Xu, Hailong Wang
Among various BPS intermediates, p-hydroxybenzenesulfonic acid is most commonly identified in BPS oxidation processes such as amorphous boron activated peroxymonosulfate (Shao, Duan, et al., 2017), photocatalysis of α-Fe2O3 nanosheets (Shao, Duan, et al., 2017), and photolysis in water (Wang et al., 2014) and nitrate solution (Cao et al., 2016). Interestingly, under the phototransformation of a 350 W xenon lamp, only one major BPS decomposition intermediate (p-hydroxybenzenesulfonic acid) was found (Wang et al., 2014), followed by p-hydroxybenzenesulfonic which is further oxidized to small molecules. These findings demonstrate that hydroxylation may be the most dominant pathway for BPS degradation. Besides, meta-cleavage was also observed in BPS decomposition by means of microbial biodegradation (Choi & Lee, 2017a). Electron transfer mechanism was proposed in the decomposition of BPS by amorphous boron activated peroxymonosulfate, in which no changes to the two phenolic rings of BPS was found until the two oxygen atoms of sulfonyl functional group were removed (Shao, Duan, et al., 2017).