The emulsion polymerization of styrene in the presence hydrophilic poly(methacrylic acid-co-poly(ethylene oxide) methyl ether methacrylate), P(MAA-co-PEOMA), macromolecular RAFT (reversible addition–fragmentation chain transfer) agents possessing a trithiocarbonate reactive group and 19 ethylene oxide subunits grafts was performed to create situ P(MAA-co-PEOMA)-b-polystyrene amphiphilic block copolymer self-assemblies. system studied using following conditions: pH 5, two different...

Abstract The syntheses of amphiphilic block copolymers are successfully performed in water by chain extension hydrophilic macromolecules with styrene at 80 °C. employed strategy is a one‐pot procedure which poly(acrylic acid), poly(methacrylic acid) or acid‐ co ‐poly(ethylene oxide) methyl ether methacrylate) macroRAFTs first formed using 4‐cyano‐4‐thiothiopropylsulfanyl pentanoic acid (CTPPA) as transfer agent. resulting then directly used without further purification for the RAFT...

One of the greatest challenges for theoretical study transition-metal-containing compounds is treatment intrinsically multiconfigurational atoms and molecules, which require a multireference (MR) in wave function theory. The accuracy density functional theory such systems still being explored. Here, we continue that exploration by presenting predictions 42 exchange-correlation (xc) functionals 11 types [local spin approximation (LSDA), generalized gradient (GGA), nonseparable (NGA),...

Density functional theory (DFT) calculations have been performed to provide the first detailed computational study on mechanism and enantioselectivity for [4 + 2] cycloaddition reaction of ketenes with N-benzoyldiazenes catalyzed by N-heterocyclic carbenes (NHCs). Two possible mechanisms studied: is "ketene-first" (mechanism A), second novel "diazene-first" B). The calculated results reveal that B more favorable than A because it not only lower energy barrier but also consistent provided...

Abstract The development of new methods for regio‐ and stereoselective activation C−O bonds in ethers holds significant promise synthetic chemistry, offering advantages terms environmental sustainability economic efficiency. Moreover, the C−N atropisomers represent a fascinating crucial chiral system, extensively found natural products, pharmaceutical leads, frameworks advanced materials. In this work, we have introduced nickel‐catalyzed enantioselective carbon‐oxygen arylation reaction...

Abstract A novel class of chiral amphiphilic bifunctional thioureas based on a beyerane scaffold and each containing primary amino group were designed synthesized from the readily available natural product isosteviol. The shown to be effective for catalyzing asymmetric Michael additions between isobutyraldehyde nitroalkenes. thiourea 1a furnished S enantiomers, whereas 1b afforded R both with high yields (up 92 %) excellent enantioselectivities 98 %). Furthermore, reactions proceeded...

The first theoretical investigation using density functional theory (DFT) methods to study the detailed reaction mechanisms of stereoselective [2 + 2 2] multimolecular cycloaddition ketene (two molecules) and carbon disulfide (CS2, one molecule) which is catalyzed by N-heterocyclic carbene (NHC) presented in this paper. calculated results indicate that occurs through four steps: complexation NHC with (channel 1a) rather than CS2 1b), addition 2b) but not dimerization 2a), formal [4 a second...

Vanadium dimer is a notoriously difficult case for Kohn–Sham (KS) density functional theory with currently available approximations to the exchange–correlation (xc) functionals, and many approximate xc functionals yield an exceedingly large error in calculated bond energy. In this paper, we first test energies estimated by 43 Hartree–Fock (HF) method. The results further confirm errors show that, experimental energy being 64.2 kcal/mol, KS calculations give predictions all over map ranging...

Abstract The development of new methods for regio‐ and stereoselective activation C−O bonds in ethers holds significant promise synthetic chemistry, offering advantages terms environmental sustainability economic efficiency. Moreover, the C−N atropisomers represent a fascinating crucial chiral system, extensively found natural products, pharmaceutical leads, frameworks advanced materials. In this work, we have introduced nickel‐catalyzed enantioselective carbon‐oxygen arylation reaction...

Reaction mechanisms of the 6-benzyl-6-azabicyclo[2.2.1]hept-2-ene with benzoyl isocyanate have been investigated using density functional theory (DFT) at B3LYP/6-31G(d,p) level theory. The reaction proceeding along six competitive channels includes two categories. That is, are formally [3,3]-sigmatropic rearrangements and four [4+2] cycloadditions. For urea, rearrangement channel cycloaddition since they similar barriers. However, energetically favorable pathways to lead isourea, highest...

Abstract BACKGROUND: 2,2′‐disbenzothiazole disulfide is widely used as a vulcanization accelerator in rubber production and an intermediate the drug industry. Its current industrial process, oxidation of 2‐mercaptobenzothiazole by sodium nitrite acidic solution, produces large quantities liquid waste water. A novel green synthetic method was developed, which dioxygen oxidant 2,2,6,6‐tetramethylpiperidyl‐1‐oxyl (TEMPO) catalyst without any metallic compounds. RESULTS: The conditions,...

The enantioselective performance of porous chiral metal–organic frameworks (CMOFs) is closely related to the pore size and uniformity easily accessible active sites. recognition efficiency microporous CMOFs hindered by restricted diffusion guest. Hierarchical with multiple regimes ranging from micropores macropores have emerged as potential candidates in separation applications. 3DOM Zn-MOF-74 crystalline material ordered macro–micropore structure was prepared a general bottom-up strategy...

Abstract Recently, chiral spiroborate ester [( R )‐2‐((1,3,2‐dioxaborolan‐2‐yloxy)methyl)pyrrolidine] has been experimentally employed as an effective catalyst in the borane‐mediated asymmetric reduction of prochiral ketones to produce corresponding secondary alcohols. In this article, we have theoretically investigated mechanism using density functional theory. The results reveal that reaction is accomplished via four steps. Fully geometry optimized reactants, products, transition states,...

Abstract The gas‐phase pyrolytic decomposition mechanisms of 3‐anilino‐1‐propanol with the products aniline, ethylene, and formaldehyde or N ‐methyl aniline aldehyde were studied by density functional theory. geometries reactant, transition states, intermediates optimized at B3LYP/6‐31G (d, p) level. Vibration analysis was carried out to confirm state structures, intrinsic reaction coordinate method performed search minimum energy path. Four possible channels are shown, including two...