The catalytic activity of β‐cyclodextrin immobilized on Dowexresin as an efficient solid‐liquid phase transfer catalyst was developed for the synthesis of alkyl thiocyanates and phenacyl derivatives in water. The nucleophilicsubstitutionreactions were performed under mild reaction condition and gave the products in excellent yields. Furthermore, the catalyst could be recycled by facile separation
Nucleophilic Substitution Reactions of Alkyl Halides by Using New Polymer-Supported Reagents Containing Hemin
作者:Kiyoshi Saito、Kaoru Harada
DOI:10.1246/bcsj.62.2562
日期:1989.8
hemin, divinylbenzene, and 2-methyl-5-vinylpyridine was synthesized by suspension copolymerization. Substitution reactions of primary, secondary, and tertiary alkylhalides with the hemin copolymer combined with cyanide, azide, and thiocyanate ions were given satisfactory yields. This reaction mechanism was revealed to be a SNi type on the basis of stereochemical study. The hemin copolymer was not only
Poly(ethylene glycol) dicationic ionic liquid‐based MnCl42− was prepared by nucleophilic substitution of poly(ethylene glycol) dichloride with methylimidazole followed by reaction with MnCl2. The structural properties of the catalyst were systematically investigated using Fourier transform infrared, UV–visible and Raman spectra and thermogravimetric analysis. The application of this catalyst allows
Iron-Catalyzed Decarboxylation of Trifluoroacetate and Its Application to the Synthesis of Trifluoromethyl Thioethers
作者:Benjamin Exner、Bilguun Bayarmagnai、Fan Jia、Lukas J. Goossen
DOI:10.1002/chem.201503915
日期:2015.11.23
Nucleophilic CF3 has been generated by decarboxylation of potassium trifluoroacetate, arguably the most easy‐to‐handle, inexpensive, and sustainable source of trifluoromethyl groups. Simple iron(II) chloride catalyzes the decarboxylation as well as a subsequent trifluoromethylation of organothiocyanates, resulting in a straightforward synthesis of trifluoromethylthioethers. The KCN byproduct is absorbed by
Synthesis of Difluoromethyl Thioethers from Difluoromethyl Trimethylsilane and Organothiocyanates Generated In Situ
作者:Bilguun Bayarmagnai、Christian Matheis、Kévin Jouvin、Lukas J. Goossen
DOI:10.1002/anie.201500899
日期:2015.5.4
A copper‐CF2H complex generated in situfrom copper thiocyanate and TMSCF2H smoothly converts organothiocyanates into valuable difluoromethylthioethers. This reaction step can be combined with several thiocyanation methods to one‐pot protocols, allowing late‐stage difluoromethylthiolations of widely available alkyl halides and arenediazonium salts. This strategy enables the introduction of difluoromethylthio