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21.
[reaction: see text] An aqueous biphasic reaction system enables the direct use of allyl alcohol in the Tsuji-Trost reaction without the help of any activating reagents for allyl alcohol. The reaction conditions are neutral to basic, allowing the use of amines as the nucleophile. Theoretical calculations have elucidated the importance of hydration of the hydroxy group for the smooth generation of pi-allylpalladium species. 相似文献
22.
Koichiro Nakanishi Susumu Okazaki Kenji Ikari Hidekazu Touhara 《Chemical physics letters》1981,84(3):428-432
Monte Carlo calculations have been carried out for pure water and an infinitely dilute aqueous solution of methanol at 298.15 K at ordinary density by the Metropolis method in NTV ensemble. The hydration structure around methanol revealed by a graphic display technique indicates a structure-forming effect near the hydrophobic group. 相似文献
23.
24.
Taisei Ueda Masumi Asahi Shin-Ichi Nagai Jinsaku Sakakibara 《Journal of heterocyclic chemistry》1996,33(1):169-172
Diazepinoquinoxalines 3, 4 and imidazolobenzopteridines 5, 6a-d, 7a-d, 8, 9 were synthesized from 3-allylamino-6,7-dimethyl-2-quinoxalinecarboxamide ( 1 ) and 2-allylamino-6,7-dimethyl-3,4-dihydrobenzo[g]pteridin-4-one ( 2 ) by the intramolecular cyclization using phenylselenenyl chloride. 相似文献
25.
The title dienylcyclopropanes smoothly rearrange of five-membered rings in the presence of a Pd(O) catalyst under mild conditions. 相似文献
26.
A. Koiwai H. Miyaji T. Asahi K. Asai Y. Miyamoto 《Journal of inclusion phenomena and macrocyclic chemistry》1986,4(3):255-264
The decomposition of urea adducts with hydrocarbons is treated as a first-order phase transition and the pressure dependence is studied up to 0.7 GPa for several kinds of adducts. The thermodynamic quantities at the decomposition of the adduct can be analysed as a sum of those quantities of the component materials. The transition from the orthorhombic to the hexagonal form of the adduct with polyethylene is also investigated by X-ray diffraction and the pressure dependence of the lattice parameters is measured for the adducts. The results are compared with the phase transition in the pure paraffin. 相似文献
27.
Intramolecular tandem Michael-type addition/aldol cyclization induced by TiCl(4)-R(4)NX combinations
[reaction: see text] Treatment of formyl alpha,beta-enones with a TiCl(4)-R(4)NX combination induces an intramolecular aldol cyclization to furnish 2-acyl-3-halocyclohexanol with three controlled consecutive stereogenic centers. The reaction of bis-alpha,beta-enones with the combination provides cyclic diketones with high stereoselectivity via an intramolecular Michael addition reaction. 相似文献
28.
Alkenylation reaction of alpha-halo carbonyl compounds with alkenylindiums proceeded via a radical process in the presence of triethylborane. Unactivated alkene moieties as well as a styryl group could be introduced by this method. The geometry of the carbon-carbon double bonds of the alkenylindiums was retained. Preparation of an alkenylindium via a hydroindation of 1-alkyne followed by radical alkenylation established an efficient one-pot strategy. [reaction: see text] 相似文献
29.
The structural characteristics of methanol in aqueous solutions, on a molecular level, can be elucidated by four types of calculation: molecular orbital, multiparametric optimization of intermolecular potential function, Monte Carlo, and molecular dynamics. As a first step, the potential between water and methanol was determined by ab initio LCAO SCF molecular orbital calculations with the STO—3G basis set and subsequent multiparametric fitting. This and water—water potentials were used for Monte Carlo calculation on an aqueous methanol solution containing a 1:216 mole ratio of methanol to water. Hydration around methanol is briefly discussed. 相似文献
30.
Treatment of 1,4‐disubstituted 1,2,3‐triazoles with aryl chlorides in the presence of potassium carbonate under palladium catalysis and microwave irradiation at 250 °C for 15 min leads to arylation of the triazole at the 5‐position. A variety of functional groups, including ester and hydroxy groups, are compatible. The procedure is suitable for the regioselective preparation of trisubstituted triazoles. Microwave irradiation accelerates the reaction, thus allowing the rapid synthesis of trisubstituted triazoles, which are difficult to synthesize selectively. 相似文献