34764-02-8Relevant academic research and scientific papers
Antimony(v) catalyzed acetalisation of aldehydes: An efficient, solvent-free, and recyclable process
Ugarte, Renzo Arias,Hudnall, Todd W.
, p. 1990 - 1998 (2017/06/09)
A highly selective, solvent-free process for the acetalisation of aldehydes was achieved by the use of a readily accessible antimony(v) catalyst which we previously prepared in our lab as a tetraarylstibonium triflate salt ([1][OTf]). High yields of the acetals were achieved in the presence of stoichimetric amounts of either triethoxymethane or triethoxysilane. It was found that triethoxymethane reactions required longer time to reach completion when compared to triethoxysilane reactions which were completed upon mixing of the reagents. The products can be easily separated from the catalyst by distillation which enabled further use of [1][OTf] in additional calytic reactions (up to 6 cycles). Moreover, [1]+ also catalyzed the deprotection of the acetals into their corresponding aldehydes using only water as a solvent.
Tuning the structure and solubility of nanojars by peripheral ligand substitution, leading to unprecedented liquid-liquid extraction of the carbonate ion from water into aliphatic solvents
Ahmed, Basil M.,Calco, Brice,Mezei, Gellert
, p. 8327 - 8339 (2016/06/01)
Nanojars, a novel class of neutral anion-incarcerating agents of the general formula [CuII(OH)(pz)]n (Cun; n = 27-31, pz = pyrazolate anion), efficiently sequester various oxoanions with large hydration energies from water. In this work, we explore whether substituents on the pyrazole ligand interfere with nanojar formation, and whether appropriate substituents could be employed to tune the solubility of nanojars in solvents of interest, such as long-chain aliphatic hydrocarbons (solvent of choice for large-scale liquid-liquid extraction processes) and water. To this end, we conducted a comprehensive study using 40 different pyrazole ligands, with one, two or three substituents in their 3-, 4- and 5-positions. The corresponding nanojars are characterized by single-crystal X-ray diffraction and/or electrospray-ionization mass spectrometry (ESI-MS). The results show that Cun-nanojars with various substituents in the pyrazole 4-position, including long chains, phenyl and CF3 groups, can be obtained. Straight chains are also tolerated at the pyrazole 3-position, and favor the Cu30-nanojar. Homoleptic nanojars, however, could not be obtained with phenyl or CF3 groups. Nevertheless, if used in mixture with the parent non-substituted pyrazole, sterically hindered pyrazoles do form heteroleptic nanojars. With 3,5-disubstituted pyrazoles, only heteroleptic nanojars are accessible. The crystal structure of novel nanojars (Bu4N)2[CO3?{Cu30(OH)30(3,5-Me2pz)y(pz)30-y}] (y = 14 and 15) is presented. We find that in contrast to the parent nanojar, which is insoluble in aliphatic solvents and water, nanojars with alkyl substituents are soluble in saturated hydrocarbon solvents, whereas nanojars based on novel pyrazoles, functionalized with oligoether chains, are readily soluble in water. Liquid-liquid extraction of carbonate from water under basic pH is presented for the first time.
A simple, efficient and general procedure for acetalization of carbonyl compounds and deprotection of acetals under the catalysis of indium(III) chloride
Ranu, Brindaban C.,Jana, Ranjan,Samanta, Sampak
, p. 446 - 450 (2007/10/03)
Indium (III) chloride efficiently catalyzes the protection of a variety of aldehydes and ketones to their corresponding 1,3-dioxolanes and dialkyl acetals in refluxing cyclohexane. On the other hand, deprotection of acetals is also achieved in refluxing aqueous methanol under the catalysis of indium(III) chloride.
Solvolysis of 1-decenyl(phenyl)iodonium tetrafluoroborate: Mechanisms of nucleophilic substitution and elimination
Okuyama, Tadashi,Imamura, Shohei,Ishida, Yoshimi
, p. 543 - 548 (2007/10/03)
Solvolysis of (E)-1-decenyl(phenyl)iodonium tetrafluoroborate 1 was carried out in some alcohols, acetic acid, and mixed aqueous alcoholic solvents at 50-60°C and the effects of added carboxylates and other salts were also examined in methanol. Reaction products include enol derivatives (substitution) and 1-decyne (elimination) as well as iodobenzene. Rates for the solvolysis increase with increasing nucleophilicity of the solvent but have no correlation with the solvent ionizing power. The substitution occurs mostly via inversion of configuration, and is concluded to follow the in-plane SN2 mechanism with a minor concomitant out-of-plane SN2 pathway. The reactions with the deuterated substrates show that stronger bases of pKa of the conjugate acid > 3 induce exclusively α-elimination of 1 in methanol. However, both α- and β-elimination occur in neutral methanol in a ratio of about 3/1 besides the substitution. Mechanisms for these reactions are proposed.
TiCl4-Catalyzed Addition of HN3 to Aldehydes and Ketones. Thermolysis and Photolysis of α-Azido Ethers
Hassner, Alfred,Fibiger, Richard,Amarasekara, Ananda S.
, p. 22 - 27 (2007/10/02)
Aldehydes react with hydrazoic acid and alcohols in the presence of catalytic amounts of TiCl4 to produce α-azido ethers.The conversion of simple ketones to methyl α-azido alkyl ethers can be accomplished by means of hydrazoic acid and methyl orthoformate.Both gas-phase thermolysis and photolysis of representative α-azido ethers were studied and shown to produce mainly imino ethers.In the thermolysis, migratory preference decreases in the series H >> CH3 > Ph >> OR.
