排序方式: 共有41条查询结果,搜索用时 31 毫秒
1.
Amadei A Marinelli F D'Abramo M D'Alessandro M Anselmi M Di Nola A Aschi M 《The Journal of chemical physics》2005,122(12):124506
In this paper we extend the perturbed matrix method by explicitly including the nuclear degrees of freedom, in order to treat quantum vibrational states in a perturbed molecule. In a previous paper we showed how to include, in a simple way, nuclear degrees of freedom for the calculation of molecular polarizability. In the present work we extend and generalize this approach to model vibroelectronic transitions, requiring a more sophisticated treatment. 相似文献
2.
Kate Lauder Silvia Anselmi Dr. James D. Finnigan Dr. Yuyin Qi Dr. Simon J. Charnock Dr. Daniele Castagnolo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(46):10422-10426
The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base. 相似文献
3.
Jorna Kalim Thibaut Duhail Dr. Ewa Pietrasiak Dr. Elsa Anselmi Dr. Emmanuel Magnier Prof. Dr. Antonio Togni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(8):2638-2642
The direct trifluoromethylation of a variety of aliphatic alcohols using a hypervalent iodosulfoximine reagent afforded the corresponding ethers in moderate to good yields (14–72 %). Primary, secondary, and even tertiary alcohols, including examples derived from natural products, underwent this transformation in the presence of catalytic amounts of zinc bis(triflimide). Typical reaction conditions involved a neat mixture of 6.0 equivalents of the alcohol with 1.0 equivalent of the reagent, with the majority of reactions complete within 2 h with 2.5 mol % of the Lewis acid catalyst. Furthermore, experimental evidence was provided that the C−O bond-forming process occurred via the coordination of the alcohol to the iodine atom and subsequent reductive elimination. 相似文献
4.
Mario Casolaro Lucia Staltari Cecilia Anselmi Raniero Mendichi Andrea Bernini 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):141-151
A poly(amido-amine), PAA, bearing β-CD units in the side chain was synthesized by a polyaddition reaction of 1,4-bis-acryloyl-piperazine with 6-monodeoxy-6-monoamino-β-cyclodextrin (β-CD-NH2). Unlike the simple β-CD-NH2 with a greater basicity constant (log K = 8.60), the polymer revealed an unusual polyelectrolyte behaviour with a lower basicity constant (log K° = 6.29) of the tertiary nitrogen atom, that is strongly dependent on the degree of protonation α of the whole macromolecule. It follows the modified Henderson–Hasselbalch equation with n = 1.75, in a wide α-range. The greater (?46.1 kJ/mol) and the lower (?27.6 kJ/mol) enthalpy (ΔH°) changes of the compounds were in line with the protonation of a primary or a tertiary nitrogen atom. The calorimetric data suggested that the PAA protonation destroyed a packing structure formed by two rigid β-CD side chains interacting head-to-head. The UV spectrophotometric data showed that the PAA exhibits affinity towards the l-ascorbic acid at low pH (pH 2.46) with an isosbestic point at 241 nm and a slight blue shift of the maximum absorption of the ascorbic acid (244 nm) on PAA additions. 相似文献
5.
6.
Pegna R Nobili AM Shao M Turyshev SG Catastini G Anselmi A Spero R Doravari S Comandi GL De Michele A 《Physical review letters》2011,107(20):200801
Mechanical oscillators can be sensitive to very small forces. Low frequency effects are up-converted to higher frequency by rotating the oscillator. We show that for 2-dimensional oscillators rotating at frequency much higher than the signal the thermal noise force due to internal losses and competing with it is abated as the square root of the rotation frequency. We also show that rotation at frequency much higher than the natural one is possible if the oscillator has 2 degrees of freedom, and describe how this property applies also to torsion balances. In addition, in the 2D oscillator the signal is up-converted above resonance without being attenuated as in the 1D case, thus relaxing requirements on the read out. This work indicates that proof masses weakly coupled in 2D and rapidly rotating can play a major role in very small force physics experiments. 相似文献
7.
Marina Briand Elsa Anselmi Guillaume Dagousset Emmanuel Magnier 《Chemical record (New York, N.Y.)》2023,23(9):e202300114
Over the last years, methods devoted to the synthesis of asymmetric molecules bearing a perfluoroalkylated chain have been limited in number. Among them, only a few can be used on a large variety of scaffolds. This microreview aims at summarizing these recent advances in enantioselective perfluoroalkylation (−CF3, −CF2H, −CnF2n+1) and highlights the need for new enantioselective methods to easily synthesize chiral fluorinated molecules which would be useful for the pharmaceutical and agrochemical industries. Some perspectives are also mentioned. 相似文献
8.
Giangiacomo Beretta Giulio Vistoli Enrico Caneva Cecila Anselmi Roberto Maffei Facino 《Magnetic resonance in chemistry : MRC》2009,47(5):456-459
The complete 1H, 13C and 15N NMR spectral assignments of two new alkaloids isolated from chestnut honey and structurally related to kynurenic acid have been made using 1‐D and 2‐D NMR techniques, including COSY, HMQC and HMBC experiments. The new compounds have been identified as 3‐(2′‐pyrrolidinyl)‐kynurenic acid and its γ‐lactam derivative. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
9.
We present a novel approach to explore the conformational space of globular proteins near their native state. It combines the advantages of coarse-grained models with those of all-atoms simulations, required to treat molecular recognition processes. The comparison between calculated structural properties with those obtained with all-atoms molecular dynamics simulations establishes the accuracy of the model. Our method has the potential to be extended to molecular recognition processes in systems whose characteristic size and time scale prevent an analysis based on all-atoms molecular dynamics. 相似文献
10.
Synthesis of 2-trifluoromethoxyethyl trifluoromethoxyacetate and derived 2-trifluoromethoxyacrylates
Jean-Claude BlazejewskiElsa Anselmi Angelika WernickeClaude Wakselman 《Journal of fluorine chemistry》2002,117(2):161-166
The synthesis of 2-trifluoromethoxyethyl trifluoromethoxyacetate 2 by oxidation of bis(2-trifluoromethoxyethyl)ether 1 followed by its anionic condensation with aldehydes, ketones and immonium salts under mild conditions, and further dehydration or deamination, enabled the preparation of 3-aryl and 3-alkyl-2-trifluoromethoxacrylates 8a-e as well as the parent 2-trifluoromethoxyacrylate 8f. 相似文献