26586-26-5Relevant articles and documents
Characterization of different reverse micelle interfaces using the reaction of 4-fluoro-3-nitrobenzoate with piperidine
Correa, N. Mariano,Durantini, Edgardo N.,Silber, Juana J.
, p. 121 - 127 (2005)
The characterization of different reverse micellar interfaces, benzene-sodium 1,4-bis-2-ethylhexylsul-fosuccinate (AOT)-water and benzene-benzyl-rt-hexadecyldimethyJammonium chloride (BHDC)-water, were studied using an aromatic nucleophilic substitution reaction, SNAr, between acid 4-fluoro-3-nitrobenzoic (FNBA) and piperidine. The reaction was also studied in homogeneous media, water and benzene, varying the ionic strength in the aqueous solution. The kinetic profiles were investigated as a function of variables such as surfactant, amine concentration and the amount of water dispersed in the reverse micelles, W0 = [water]/[surfactant]. In the pure solvents, water and benzene, there is no genuine base-catalyzed reaction. In water the reaction is faster than in benzene, owing to the better stabilization of the intermediate Z. Also, the reaction rate in water is accelerated by the addition of salt. In both micellar systems FNBA is totally incorporated in the interface of the aggregate because, under the working conditions of excess of amine, it is ionized to carboxylate, The reactions kinetics in these media can be quantitatively explained taking into account the distribution of the nucleophile between the bulk solvent and the micelle interfaces. In the AOT reverse micelles at W0= 10, the anionic substrate seems to be located in the water side of the interface whereas in BHDC it resides in the oil side of the interface. The results were used to evaluate the intrinsic second-order rate coefficient of the SNAr reaction at the interface. From these data, properties such as micropolarity and ionic strength of this environment can be deduced. Hence, as expected, the micropolarity of the reverse micelles systems is higher than that of pure benzene and increases upon water addition. In the AOT system and owing to the location of the probe, the average ionic strength of the AOT reverse micelles could be estimated and a value of around 4.5 M was found. Copyright
Copper(ii)-catalyzed c-n coupling of aryl halides and n-nucleophiles promoted by quebrachitol or diethylene glycol
Chen, Guoliang,Chen, Yuanguang,Du, Fangyu,Fu, Yang,Wu, Ying,Zhou, Qifan
supporting information, p. 2161 - 2168 (2019/11/25)
Herein, we report the natural ligand quebrachitol (QCT) as a promoter for a Cu(II) catalyst, which is highly effective for N-Arylation of various amines and related aryl halides. A series of diarylamine derivatives were obtained in high yields by using diethylene glycol (DEG) as both ligand and solvent. The C-N coupling reactions proceed under mild conditions and exhibit good functional group tolerance.
OXADIAZOLE DERIVATIVES
-
Page/Page column 117-118, (2009/05/29)
The invention relates to compounds of formula (I): wherein R1, R2, Ra, Rb, W, Q and S have the meanings given in claim 1. The compounds are useful e.g. in the treatment of autoimmune disorders, such as multiple sclerosis.
