对芳香酸基深共熔溶剂(DESs)的形成和萃取脱硫(EDS)机理进行了实验研究,并通过量子化学计算进行了研究。研究了氢键和范德华力作为形成芳酸基DES的驱动力,方法如下:11 H NMR和FTIR光谱以及DFT计算。还研究了EDS的驱动力。结果表明,范德华力和其他弱相互作用是EDS的主要潜水力,而EDS后芳酸基DES的结构没有改变。通过DFT计算芳族酸基DES与噻吩(TH),苯并噻吩(BT)和二苯并噻吩(DBT)之间的相互作用能,以了解EDS顺序:TH
Studies related to cephalosporins. Part 2 . Displacement reactions on 3-bromomethylcephems with salts of carboxylic acids
作者:Maurizio Botta、Francesco De Angelis、Ingeborg Grgurina、Mauro Marzi、Rosario Nicoletti
DOI:10.1002/jhet.5570220414
日期:1985.7
The reactivity of Δ3- and Δ2-3-bromomethylcephems toward carboxylate nucleophiles has been studied. The Δ3-bromomethylcephem 1, less reactive than the Δ2-analogue 4, is converted in high yields into 3-acyl-oxymethyl-3-cephems 2a-d, generally with no isomerization of the double bond, only within a narrow range of conditions. In particular, the Δ3-7-aminocephalosporanic acid (7-ACA) derivative 2a has
Mechanistic Studies of the O<sub>2</sub>-Dependent Aliphatic Carbon−Carbon Bond Cleavage Reaction of a Nickel Enolate Complex
作者:Lisa M. Berreau、Tomasz Borowski、Katarzyna Grubel、Caleb J. Allpress、Jeffrey P. Wikstrom、Meaghan E. Germain、Elena V. Rybak-Akimova、David L. Tierney
DOI:10.1021/ic1017888
日期:2011.2.7
Overall, I is a reasonable structural model for the ES adduct formed in the active site of NiIIARD. However, the presence of phenyl appendages at both C(1) and C(3) in the [PhC(O)C(OH)C(O)Ph]− anion results in a reaction pathway for O2-dependent aliphatic carbon−carbon bond cleavage (via a trione intermediate) that differs from that accessible to C(1)−H acireductone species. This study, as the first detailed
METHODS OF RING OPENING POLYMERIZATION AND CATALYSTS THEREFOR
申请人:Coady Daniel Joseph
公开号:US20120046437A1
公开(公告)日:2012-02-23
A salt catalyst comprises an ionic complex of i) a nitrogen base comprising one or more guanidine and/or amidine functional groups, and ii) an oxoacid comprising one or more active acid groups, the active acid groups independently comprising a carbonyl group (C═O), sulfoxide group (S═O), and/or a phosphonyl group (P═O) bonded to one or more active hydroxy groups; wherein a ratio of moles of the active hydroxy groups to moles of the guanidine and/or amidine functional groups is greater than 0 and less than 2.0. The salt catalysts are capable of catalyzing ring opening polymerization of cyclic carbonyl compounds.
Effect of conformation and stereochemistry in substitution reactions of fused chlorocyclobutanones: oxyallyl cation intermediates
作者:Alfred Hassner、John L Dillon、Larry R Krepski、Kay D Onan
DOI:10.1016/s0040-4039(00)86385-6
日期:1983.1
Fused α-acyloxycyclobutanones, whose conformation and stereochemistry have been unambiguously established by X-ray analysis, undergo an unusual displacement with methoxide as nucleophile to produce α-methoxycyclobutanones. The success of this reaction, which suggests the intermediacy of an oxyallyl cation, is highly dependent on conformational and steric factors.
Analogues of RNA and DNA compounds contain a neutral, stereoregular linking group based on replacement of the phosphoryl with a sulfonyl group. Precursors to the analogues are also described, as are methods for preparing the precursors and analogues.