Recent trends in incorporation of CO2 into organosulfur compounds via C-S bond cleavage.

Desulfurative functionalization of organosulfur compounds to form various carbon-carbon and carbon-heteroatom bonds has become established as a powerful tool in organic chemistry. In this context, desulfurative carboxylation of this class of compounds using carbon dioxide (CO2) as a sustainable and renewable source of carboxyl has recently been developed as an efficient option for the synthesis of carboxylic acid derivatives. The aim of this Focus Review is to summarize the major progress in this appealing research field with particular emphasis on the mechanistic features of the reactions. Literature has been surveyed until the end of February 2024, according to the data collected using SciFinder and Google Scholar engines.

Advancements in double decarboxylative coupling reactions of carboxylic acids.

The double decarboxylative coupling reaction between two (similar or different) molecules of carboxylic acids is an emerging area that has gained considerable attention as a new avenue for forging carbon-carbon bonds. Since this synthetic strategy only utilizes carboxylic acids as easily accessible, non-toxic and stable starting materials, and extrudes carbon dioxide (CO2) as the only waste by-product, it can be considered as an environmentally benign alternative to traditional coupling reactions which mainly rely on the use of toxic organic halides or organometallic reagents. The aim of this review is to highlight the recent advances and developments in this exciting new field that may serve as inspiration for future research to mature it.

Recent investigations into deborylative (thio-/seleno-) cyanation of aryl boronic acids.

In this review, we intend to summarize the most important discoveries in the deborylative (thio-/seleno-) cyanation of aryl boronic acids from 2006 to the end of 2023. Thus, the review is divided into three parts. The first section focuses exclusively on cyanation of aryl boronic acids into aryl nitriles. The second section covers the available literature on the synthesis of aryl thiocyanates through thiocyanation of respective aryl boronic acids. The third will discuss selenocyanation of aryl boronic acids into aryl selenocyanates.

Exploring porphyrins induced carbon nanocone TM-PICNC (TM = Sc2+, Ti2+, V2+, Cr2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) as a highly sensitive sensor for CO2 gas detection in presence O2 and H2O molecules: a computational study.

This study investigated the adsorption of CO2 molecules on transition metal ions (TM) porphyrins induced carbon nanocone (TM-PICNC) (TM = Sc2+, Ti2+, V2+, Cr2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) using density functional theory (DFT) to determine the stabilities, energetic, structural, and electronic properties. The results showed that the CO2 molecule is adsorbed on TM-PICNC with adsorption energies ranging from 0.03 to -12.12 kcal/mol. The weak interactions of CO2 gas with Cr, Ni, Cu, and Zn-PICNC were observed, while strong adsorption was found on Sc, Ti, and V-PICNC. The Ti, V, and Cr-PCNC structures were shown to have a suitable energy gap (Eg) for sensing ability because of the effective and physical interaction between these structures and CO2 gas, leading to a short recovery time. DFT calculations also revealed that V-PCNC had a high %ΔEg (about %56.79) and hence high sensitivity to CO2 gas, making it a promising candidate for having good sensing ability to CO2 gas in presence of O2 and H2O gas.

Recent progress in reductive carboxylation of C-O bonds with CO2.

Transformation of carbon dioxide (CO2) into value-added organic compounds has attracted increasing interest of scientific community in the last few decades, not only because CO2 is the primary greenhouse gas that drives global climate change and ocean acidification, but also because it has been regarded as a plentiful, nontoxic, nonflammable and renewable one-carbon (C1) feedstock. Among the various CO2-conversion processes, carboxylation reactions represent one of the most beautiful and attractive research topics in the field, since it offers the possibility for the construction of synthetically and biologically important carboxylic acids from various easily accessible (pseudo)halides, organosilicon, and organoboron compounds. The purpose of this review is to summarize the available literature on deoxygenative carboxylation of alcohols and their derivatives utilizing CO2 as a carboxylative reagent. Depending on the C-O compounds employed, the paper is divided into five major sections. The direct dehydroxylative carboxylation of free alcohols is discussed first. This is followed by reductive carboxylation of carboxylates, triflates, and tosylates. In the final section, the only reported example on catalytic carboxylation of fluorosulfates will be covered. Notably, special attention has been paid on the mechanistic aspects of the reactions that may provide new insights into catalyst improvement and development, which currently mainly relies on the use of transition metal catalysts.

Reductive coupling of nitro compounds with boronic acid derivatives: an overview.

The purpose of this review is to summarize the current literature on reductive C-N coupling of nitro compounds and boronic acids, with special emphasis on the mechanistic features of the reactions. The metal-catalyzed reactions are discussed first. This is followed by electro-synthesis and organophosphorus-catalyzed reactions. Finally, the available examples of catalyst-free reactions will be covered at the end of this review.

Theoretical study on efficient HF gas sensing by functionalized, decorated, and doped nanocone strategy.

Hydrogen fluoride (HF) is a highly dangerous and corrosive gas that can cause severe burns and respiratory damage. The density functional theory method (DFT) used to study the interaction between the HF gas and the surface of a carbon nanocone (CNC) doped with gallium atom as a chemical sensor. The results showed that CNC wasn't a good candidate to sense the HF gas and consequently its electrical properties are changed insignificant. To improve the properties of the CNC, several strategies were tried: functionalizing by pyridinol (Pyr) and pyridinol oxide (PyrO), decorated with metals (M = B, Al, and Ga), and doped with element of third group (M = B, Al, and Ga). The obtained data demonstrated that the promising results were obtained by doping the CNC with Ga atom. After full optimization, we achieved one stable configuration between the HF gas and CNC-Ga structure (S15 configuration) with Eads = -19.86 kcal/mol. The electronic properties of the CNC-Ga structure is sensible changed after the HF molecule is adsorbed. According to calculated the energy gap between HOMO and LUMO orbitals of S15 configuration are increased which could be applied a chemical signal. Eventually, one could propose that the CNC-Ga has the ability to act as a Φ-type sensor based on its physical adsorption energy and quick recovery time and doped with gallium atom is a promising strategy.

Aryl fluorosulfates: powerful and versatile partners in cross-coupling reactions.

Aryl fluorosulfates are versatile building blocks in organic synthesis and have gained increasing attention in SuFEx (Sulfur Fluoride Exchange) click chemistry. They are easily and conveniently prepared from phenols using sulfuryl fluoride SO2F2 as a low-cost sulfonyl fluoride provider. Recently, they served as less toxic and more atom economical alternatives to triflates in an impressive number of carbon-carbon and carbon-heteroatom cross-coupling reactions. In this review, we summarize the current advances and developments in applying aryl fluorosulfates as electrophilic partners in cross-coupling reactions.

Metalloporphyrin reduced C70 fullerenes as adsorbents and detectors of ethenone; A DFT, NBO, and TD-DFT study.

In the present work, the structure and electronic properties of Ti-, Cr-, Fe-, Ni-, Zn-, and Cu-inserted in porphyrin-reduced C70 fullerenes (TM-PIC70Fs) and their interactions with the ethenone were studied using DFT, NBO, and TD-DFT at CAM-B3LYP/6-31G(d) level of theory. 2.89-3.83 and 4.02-4.56 eV were obtained for the HOMO-LUMO gap energies and work functions of TM-PIC70Fs, respectively, compared with 3.76 and 4.54 eV for PIC70F. Among considered TM-PIC70Fs, the adsorption of the ethenone on Ti-PIC70F appreciably changed the HOMO-LUMO energy gap and work function. Consequently, Ti-PIC70F may be used as the ethenone's electronic conductivity and work function types sensor. According to calculated UV-visible spectra, the ethenone adsorption may change the color of Fe- and Ti-PIC70Fs. Therefore, they can be used as color-changing sensors of ethenone. In addition, Ti-, Cr-, Fe-, and Zn-PIC70Fs can be employed as suitable adsorbents of ethenone. Among proper sensors and adsorbents of ethenone, Cr-, Fe-, and Zn-PIC70Fs may be recovered and reused.

Adsorption of O2 molecule on the transition metals (TM(II) = Sc2+, Ti2+, V2+, Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) porphyrins induced carbon nanocone (TM(II)PCNC).

In this work, the adsorption of the O2 molecule on the transition metals (TM(II) = Sc2+, Ti2+, V2+, Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) porphyrins induced carbon nanocone (TM(II)-PCNC) were investigated using density functional theory (DFT) in terms of stabilities, energetic, structural, and electronic properties. It has been found that the O2 molecule is adsorbed on the TM(II)-PCNC with adsorption energies in the range of 0.29 to -98.32 kcal/mol. The interaction between the O2 gas and the Sc-PCNC molecule from the outer site is the strongest. The interaction of the O2 gas over the Ni-PCNC molecule from both outer and inner sites is the weakest. It can be concluded that the suitable interaction energy (Eg) for sensing ability attributed to the Zn-PCNC because an effective and physical interaction between Zn-PCNC and the O2 gas leads to short recovery time. DFT calculations also clarified that the high %ΔEg of Zn-PCNC and hence the high sensitivity to the O2 gas confirm that the Zn-PCNC molecule is a promising candidate for having a good sensing ability to the O2 gas.

Butadiyne-linked porphyrin nanoring as a highly selective O2 gas sensor: A fast response hybrid sensor.

The butadiyne-linked six-metalloporphyrin nanoring (Mg6-P6) and it's complex with a hexapyridyl template, Mg6-P6·T6 have a great potential for employment in future nanoelectronic applications such as a nanosensor for small gas molecules. The goal of this study is to scrutinize and improvement of the CO, N2, and O2 gas sensing capacity of Mg6-P6 and Mg6-P6·T6 using DFT calculations at CAM-B3LYP/6-31G (d,p) level of theory. The geometrical structures, binding energies, band gaps, the density of states (DOS), adsorption energies, HOMO and LUMO energies, Fermi level energies (EFL), NBO, FMO and TD-DFT spectrum were calculated to predict gas adsorption properties of Mg6-P6 and Mg6-P6·T6 systems. Based on the calculated adsorption energies and remarkable decrease in the Eg, it is expected that the Mg6-P6 and Mg6-P6·T6 are sensitive to O2 molecule. Surprisingly, the Mg6-P6-O2 and specially the Mg6-P6.T6-O2 record promising values of recovery times for different attempt frequencies. Therefore, the results open a way for the development of a new and selective O2 nanosensor in the presence of CO and N2 gas molecules.

Direct selenosulfonylation of unsaturated compounds: a review.

In this review, we have discussed recent developments on the direct selenosulfonylation of unsaturated compounds which lead to the formation of two new carbon-sulfur and carbon-selenium bonds in a single operation. The reactions were classified based on the type of starting unsaturated compound and product. Thus, the review is divided into three major sections. The first describes the current literature on selenosulfonylation of alkenes. The second section covers the available literature on selenosulfonylation of alkynes. The third focuses exclusively on selenosulfonylation of allenes.

Carbon fixation of CO2 via cyclic reactions with borane in gaseous atmosphere leading to formic acid (and metaboric acid); A potential energy surface (PES) study.

Carbon dioxide (CO2), a stable gaseous species, occupies the troposphere layer of the atmosphere. Following it, the environment gets warmer, and the ecosystem changes as a consequence of disrupting the natural order of our life. Due to this, in the present reasearch, the possibility of carbon fixation of CO2 by using borane was investigated. To conduct this, each of the probable reaction channels between borane and CO2 was investigated to find the fate of this species. The results indicate that among all the channels, the least energetic path for the reaction is reactant complex (RC) to TS (A-1) to Int (A-1) to TS (A-D) to formic acid (and further meta boric acid production from the transformation of boric acid). It shows that use of gaseous borane might lead to controlling these dangerous greenhouse gases which are threatening the present form of life on Earth, our beautiful, fragile home.

Strategies for the direct oxidative esterification of thiols with alcohols.

This review paper provides an overview of the main strategies for the oxidative esterification of thiols with alcohols. The review is divided into two major parts according to final products. The first includes the methods for the synthesis of sulfinic esters, while the second contains the procedures for the fabrication of sulfonic ester derivatives.

Methods for Direct Reductive N-Methylation of Nitro Compounds.

Direct reductive N-methylation of inexpensive and readily available nitro compounds as raw material feedstocks is more attractive and straightforward compared with conventional N-methylation of amines to prepare biologically and pharmaceutically important N-methylated amine derivatives. This strategy for synthesis of N-methylamines avoids prepreparation of NH-free amines and therefore significantly shortens the separation and purification steps. In recent years, numerous methylating agents and catalytic systems have been reported for this appealing transformation. Thus, it is an appropriate time to summarize such advances. This review elaborates on the most important discoveries and advances in this research arena, with special emphasis on the mechanistic aspect of reactions that may provide new insights into catalyst improvement.

Density functional theory studies on C20 with substitutional TinNn impurities.

In this paper, we have performed systematic theoretical surveys of C20 and its C20-2nTinNn nanocages with n = 1-8 at DFT. Full optimization indicates none of the structures collapse to open deformed as segregated heterofullerene. Also, in order to avoid the resulted strain of fused five-pentagon configuration, some of them deform their cage at the Ti-N bonds and appear cubic-like. Binding energy (Eb) increases, and the absolute heat of atomization │ΔHat│ of the designed C20-2nTinNn structures decreases, respectively, as the number of substituting Ti-N units increases. The calculated Eb of 57.05 eV/atom and │ΔHat│ of 2437.40 kcal/mol display C4Ti8N8 as the most thermodynamic stable heterofullerene where including eight separated Ti-N units through two double C═C bonds. In contrast, the calculated band gap of 2.06 eV shows C18Ti1N1 as the best-insulated heterofullerene. Here isolable or extractable open-shell C18Ti1N1 heterofullerene must be kinetic stable species, and closed-shell C4Ti8N8 should be thermodynamic stable species. Compared to the suggested Ti-decorated B38 fullerene as a high capacity hydrogen storage material with large Eb (5.67 eV/atom), our studied C20-2nTinNn heterofullerenes show the higher Eb with a range of 13.78 to 57.05 eV/atom, the higher stability, and the higher capacity hydrogen storage. Each Ti-N unit can bind up to two hydrogen molecules with an average adsorption energy of 0.073 eV/H2. While the C4Ti8N8 fullerene substituted with 8 Ti-N units can store 16 H2 molecules, the hydrogen gravimetric density (the hydrogen storage capacity) reaches up to 5.61 wt% with an average adsorption energy of 0.587 eV/H2. Based on these results, we infer that C4Ti8N8 fullerene is a potential material for hydrogen storage with high capacity and might motivate active experimental efforts in designing hydrogen storage media.

Substitution effects via aromaticity, polarizability, APT, AIM, IR analysis, and hydrogen adsorption in C20-nTin nanostructures: a DFT survey.

In this paper, the substitution effects of titanium heteroatom(s) on aromaticity, the average isotropic polarizability (< α >), the atomic polar tensor (APT) charge, the electrostatic potential (ESP) map, and the atoms in molecule (AIM) analysis along with infrared (IR) spectroscopy of C20 fullerene and its C20-nTin derivatives (n = 1-5) are probed via density functional theory (DFT). The nucleus-independent chemical shifts (NICS) specify that substitution effect causes more aromaticity character of the optimized heterofullerenes than benzene molecule and higher APT charge distribution upon surfaces of them than pure cage. The highest negative and positive APT charge distribution on carbons of C15Ti5 and titanium substitutions of C16Ti4-2 implies that these sites can be attacked more readily by electrophilic and nucleophilic regents, respectively. We are very pleased to state that isolating the Ti-Ti single bonds by intermediacy of one or two C atoms is an applicable strategy for attaining the highest APT charge distribution on Ti atoms of C16Ti4-2 as suitable hydrogen storage. AIM analysis of the studied C20-nAln derivatives signifies the highest electron density (ρ (r)) of 0.294 a.u. and the highest positive Laplacian of electron density (∇2ρ (r)) of 0.190 a.u., at bond critical points (BCPs) of C-Ti bond in the most stable C19Ti1 species. This heterofullerene shows the lowest < α > between the studied structures. IR spectroscopy shows that exclusive of C16Ti4-1 (as transition state), the other optimized hollow cages (as global minima) have no imaginary frequency.

Investigation of fused remote N-heterocyclic silylenes (frNHSis), at DFT.

We compared and contrasted the ΔΕs-t, band gap (ΔΕHOMO-LUMO), aromaticity, charge distribution, and reactivity of singlet (s) and triplet (t) benzopyridine-4-ylidene as the fused remote N-heterocyclic carbene (frNHC) and frNHSis with different fused aromatic rings, at (U)B3LYP/AUG-cc-pVTZ and (U)M06-2X/AUG-cc-pVTZ levels of theory. In this investigation, we found (1) all s and t divalent states appear as minimum structures, for having no negative force constant. Nonetheless, only singlets present more thermodynamic stability than their triplet analogous; (2) the trend of ΔΕs-t in kcal/mol is ortho-pyrrole (52.94) > ortho-furan (51.84) > ortho-thiophene (50.38) > para-furan (49.36) > para-pyrrole (49.00) > para-phosphole (48.67) ≥ para-thiophene (48.64) > benzene (44.33) > ortho-phosphole frNHSi (27.50), while ΔΕs-t of frNHC is 15.65 kcal/mol; (3) apart from phosphole frNHSis, the order of ΔΕs-t in a "ortho position or zigzag array" about 1.8-4.0 kcal/mol is more than that of in a "para position or chair array"; (4) the highest ΔΕHOMO-LUMO is demonstrated by ortho-pyrrole frNHSi (95.65 kcal/mol) while the lowest ΔΕHOMO-LUMO is verified by the reference frNHC (63.44 kcal/mol); (5) in contradiction of frNHC, all singlet frNHSis reveal higher band gap and lower global reactivity than their triplet congeners; (6) charge distribution along with MEP maps indicate differentially electronic cloud in middle of rings frNHSis vs. frNHC; (7) we anticipate higher nucleophilicity and lower electrophilicity of triplet frNHSis than singlet congeners, will make them worthy of synthetic surveys.

Hexa-cata-hexabenzocoronene nanographene as a promising anode material for Mg-ion batteries.

We investigated the possible use of a hexa-cata-hexabenzocoronene nanographene (HCHN) as an anode material for Mg-ion batteries (MIBs) implementing the B3LYP-gCP-D3/6-31G* scheme. The Mg cation or atom is adsorbed on the HCHN with the adsorption energy of - 200.3 or - 4.7 kcal/mol. The energy barrier related to transferring Mg cation on the HCHN surface was calculated to be 7.5 kcal/mol, producing the diffusion coefficient of 1.90 × 10-8 cm2/s. It shows that the ion mobility is high and the rate of charge or discharge is fast. The calculated specific storage capacity of HCHN is 589.4 mAh/g and the great cell voltage is 4.23 V that is generated by the interaction of cation-π between Mg2+ and HCHN, which is strong. The HCHN is considered an ideal candidate to be used as an anode material in MIBs since its storage capacity and ion mobility are high, and it has a large cell voltage.

Hydroxysulfonylation of alkenes: an update.

The direct difunctionalization of inexpensive and widely available alkenes has been recognized as a strong and straightforward tool for the rapid fabrication of complex molecules and pharmaceutical targets by introducing two different functional groups on adjacent carbon atoms of common alkene moieties in a single operation. This synthetic strategy avoids the purification and isolation of the intermediates and thus makes synthetic schemes shorter, simpler and cleaner. In this family of reactions, the hydroxysulfonylation of alkenes has emerged as an increasingly promising strategy for the synthesis of ß-hydroxysulfones, which are found in many biologically important molecules and widespread applications in organic synthesis. The objective of this review is to illustrate the advancements in the field of hydroxysulfonylation of alkenes with special emphasis on the mechanistic details of the reaction pathways.