Ring-opening reactions of 1,4-diazabicyclo[2.2.2]octane (DABCO) derived quaternary ammonium salts with phenols and related nucleophiles
作者:Nenad Maraš、Slovenko Polanc、Marijan Kočevar
DOI:10.1039/c1ob06676e
日期:——
1,4-Diazabicyclo[2.2.2]octane (DABCO) has been evaluated as a starting material for the synthesis of 1-alkyl-4-(2-phenoxyethyl)piperazines and related derivatives. We found that 1-alkyl-1,4-diazabicyclo[2.2.2]octan-1-ium salts, resulting from the alkylation of DABCO, efficiently react with a variety of nucleophiles in polyethyleneglycol (PEG) or diglyme at high temperatures to give piperazine products
Dealkylation of quaternary ammonium salts by thiolate anions: A model of the cobalamin-independent methionine synthase reaction.
作者:Ellen Hilhorst、Tjoe B.R.A. Chen、Atef S. Iskander、Upendra K. Pandit
DOI:10.1016/s0040-4020(01)85267-4
日期:1994.1
The reactions of thiolate ions derived from thiophenol and homocysteine with substituted quaternary ammonium salts result in alkyl transfer from nitrogen to sulfur. A radical mechanism for this transalkylation, accounts for the reactivity pattern of the substrate salts. In a model study of the cobalamin-independent methionine synthase reaction, 5,5,6,7-tetramethyl-5,6,7,8-tetrahydropteridinium salt
衍生自硫酚和高半胱氨酸的硫醇根离子与取代的季铵盐的反应导致烷基从氮转移到硫。这种烷基转移的自由基机理解释了底物盐的反应模式。在不依赖钴胺素的蛋氨酸合酶反应的模型研究中,可以将5,5,6,7-四甲基-5,6,7,8-四氢opter啶鎓盐(25)视为天然辅酶5的模型。使CH 3 H 4-叶酸盐(1)与高半胱氨酸的硫醇盐反应,结果观察到蛋氨酸的形成具有良好的产率。这些结果表明,在酶促过程中,N(5)-CH 3 N(5)与亲电试剂或质子在活性位点的配位可激活甲基键的甲基键。
An Efficient and Selective Oxidation of Benzylic Alcohols to the Corresponding Carbonyl Compounds under Solvent-Free Conditions
作者:Abdol Reza Hajipour、Shadpour E. Mallakpour、Iraj Mohammadpoor-Baltork、Sepideh Khoee
DOI:10.1246/cl.2000.120
日期:2000.2
1-Benzyl-4-aza-1-azoniabicyclo[2.2.2]octanedichromate is a useful reagent for selective oxidation of benzylicalcohols and α-hydroxy ketones to the corresponding carbonyl compounds. The reaction was carried out under solvent-free conditions without or in the presence of a catalytic amount of aluminum chloride.
Sonogashira reactions catalyzed by a new and efficient copper(I) catalyst incorporating N-benzyl DABCO chloride
作者:Abdol R. Hajipour、Fatemeh Mohammadsaleh
DOI:10.1016/j.tetlet.2014.03.120
日期:2014.6
developed for the palladium-free Sonogashira cross-couplingreactions of phenylacetylene with a variety of aryl halides. In this homogeneous catalytic system, 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octanechloride, a quaternary ammonium salt containing a coordinating center, plays an important role and increases the efficiency of Cu(I) species during the reaction. A number of internal alkynes were produced
A palladium catalyst was synthesized using N‐benzyl DABCO chloride and palladium chloride. The structure of this catalyst was characterized and then the catalyst was used in Suzuki cross‐ coupling reaction of different aryl halides with arylboronic acids. All substrates afforded the corresponding products in good to high yields in the presence of low amounts of the catalyst. Under the heating conditions