Applications of surfactant-modified clays to synthetic organic chemistry
摘要:
Two triphase catalysts (SLL) have been developed for organic phase-aqueous phase reactions catalyzed by Suitable modified clay (solid phase). These triphase catalysts have been applied to nucleophilic displacement on activated (benzylic) as well as unactivated organic halides and provide a convenient and effective method of preparation of the corresponding products. Other useful transformations to. which these triphase catalysts have been successfully applied are the synthesis of 9,9-dichloro bicyclo[6,1,0]nonane, O-alkylation and C-alkylation of beta-naphthol. (c) 2005 Elsevier Ltd. All rights reserved.
Protic onium salts-catalyzed synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 under mild conditions
作者:Zhen-Zhen Yang、Yu-Nong Li、Yang-Yang Wei、Liang-Nian He
DOI:10.1039/c1gc15581d
日期:——
Protic onium salts, e.g.pyridium iodide, proved to be highly efficient and recyclable catalysts for the selective synthesis of 5-aryl-2-oxazolidinones under a CO2 atmosphere at room temperature, presumably due to aziridine activation assisted by hydrogen bonding on the basis of 1H NMR and in situ FT IR under CO2 pressure study.
Synthesis of <i>N</i>
-alkyl-<i>N</i>
′-aryl or Alkenylpiperazines: A Copper-Catalyzed C-N Cross-Coupling in the Presence of Aryl and Alkenyl Triflates and DABCO
introduction of an aryl and alkyl motif onto the piperazine is not always straightforward, direct arylation and alkenylation of 1,4‐diaza‐bicyclo[2.2.2]octane would obviate the inefficiencies associated with the preparation of these target molecules. We have utilized alkyl halides, aryl or alkenyl triflates, and 1,4‐diaza‐bicyclo[2.2.2]octane for the synthesis of N‐alkyl‐N′‐aryl or alkenylpiperazines
Synthesis of New Lewis Basic Room-Temperature Ionic Liquids by Monoquaternization of 1,4-Diazabicyclo[2.2.2]octane (DABCO)
作者:Stephen MacNeil、Angela Wykes
DOI:10.1055/s-2006-956460
日期:2007.1
Sixteen new ionic liquids, including three room temperature ionic liquids, possessing cations derived from monoquaternization of DABCO have been identified through systematic variation of cation alkyl chain length and anion structure. The DABCO salts are obtained in good to excellent yields and show melting point trends, with respect to cation alkyl chain length, consistent with those reported for the imidazolium series of ionic liquids.
Easily prepared DABCO-derived (1,4-diazobicyclo[2.2.2]octane) basic ionic liquids were developed for an efficient synthesis of dimethyl carbonate (DMC) via the transesterification of ethylene carbonate (EC) with methanol. 1-Butyl-4-azo-1-azoniabicyclo[2.2.2]octane hydroxide ([C(4)DABCO]OH) exhibited high catalytic activity and 81% DMC yield together with 90% EC conversion was obtained under mild reaction conditions. Notably, the catalyst could be recycled for four times without loss of catalytic activity. Moreover, a possible mechanism was also discussed. (C) 2010 Elsevier Ltd. All rights reserved.
Hajipour, Abdol R.; Bagheri, Hamid R.; Ruoho, Arnold E., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2005, vol. 44, # 3, p. 577 - 580
作者:Hajipour, Abdol R.、Bagheri, Hamid R.、Ruoho, Arnold E.