Rearrangement of a Mesylate Tropane Intermediate in Nucleophilic Substitution Reactions. Synthesis of Aza-Bicyclo[3.2.1]octane and Aza-Bicyclo[3.2.2]nonane Ethers, Imides, and Amines
Abstract:Nucleophilic substitution of 2beta-mesyloxymethyl-N-methyl-3beta-p-tolyl-tropane intermediate with alkoxides, metal imides, or amines was found to lead not only to the expected bicyclo[3.2.1]octane (tropane) ether, imide, and amine derivatives but also to unexpected bicyclo[3.2.2]nonane derivatives. When alkoxides were used as nucleophile, only the rearranged bicyclo[3.2.2]nonane structure was obtained, whereas the use of amines or imides as nucleophile afforded a mixture of the two structures. The bicyclo[3.2… Show more
“…The hydrophilic ending groups (i.e., nucleophilic reagent) of the catalysts are located inside the micelle group where the hydrophobic ending groups of the catalysts are facing outward intimating with the organic solvent. For this, the nucleophilic reaction is retarded. − 5 Effect of the amount of TBAB catalyst on the two apparent rate constants, k app,1 and k app,2 . 6 Plot of surface tension of organic solvent with different amounts of phase-transfer catalysts at 45 °C; same conditions as given in Figure .…”
Section: Resultsmentioning
confidence: 99%
“…For this, the nucleophilic reaction is retarded. [18][19][20][21] (v) Effect of the Amount of KOH. KOH can reduce the amount of water available for anion hydration and force the catalyst from the aqueous phase to the organic phase.…”
The phase-transfer catalyzed etherification of 4,4‘-bis(chloromethyl)-1,1‘-biphenyl was investigated in an alkaline aqueous
solution/organic solvent two-phase medium. During or after
completion of the reaction, the monosubstituted product (4,4‘-(butoxymethyl chloromethyl)-1,1‘-biphenyl) and disubstituted
product (4,4‘-bis(butoxymethyl)-1,1‘-biphenyl) were both produced. The reaction was enhanced by adding a small quantity
of quaternary ammonium salt. A generalized model, which
included the aqueous- and organic-phase reactions, the mass
transfer of regenerated catalyst and active catalyst, and the
phase equilibria of the regenerated catalyst and the active
catalyst between two phases, was built up to describe the system
performance. The purpose of this work is to examine effects of
agitation, amount of organic solvent, quaternary ammonium
salts, amount of tetrabutylammonium bromide, amount of
potassium hydroxide, amount of water, organic solvents, and
temperature on the conversion of the reactant. The kinetics are
well described by a pseudo-first-order rate law. A rational
explanation of the results was made. Products of high purity
were also obtained using pressurized column chromatography.
“…The hydrophilic ending groups (i.e., nucleophilic reagent) of the catalysts are located inside the micelle group where the hydrophobic ending groups of the catalysts are facing outward intimating with the organic solvent. For this, the nucleophilic reaction is retarded. − 5 Effect of the amount of TBAB catalyst on the two apparent rate constants, k app,1 and k app,2 . 6 Plot of surface tension of organic solvent with different amounts of phase-transfer catalysts at 45 °C; same conditions as given in Figure .…”
Section: Resultsmentioning
confidence: 99%
“…For this, the nucleophilic reaction is retarded. [18][19][20][21] (v) Effect of the Amount of KOH. KOH can reduce the amount of water available for anion hydration and force the catalyst from the aqueous phase to the organic phase.…”
The phase-transfer catalyzed etherification of 4,4‘-bis(chloromethyl)-1,1‘-biphenyl was investigated in an alkaline aqueous
solution/organic solvent two-phase medium. During or after
completion of the reaction, the monosubstituted product (4,4‘-(butoxymethyl chloromethyl)-1,1‘-biphenyl) and disubstituted
product (4,4‘-bis(butoxymethyl)-1,1‘-biphenyl) were both produced. The reaction was enhanced by adding a small quantity
of quaternary ammonium salt. A generalized model, which
included the aqueous- and organic-phase reactions, the mass
transfer of regenerated catalyst and active catalyst, and the
phase equilibria of the regenerated catalyst and the active
catalyst between two phases, was built up to describe the system
performance. The purpose of this work is to examine effects of
agitation, amount of organic solvent, quaternary ammonium
salts, amount of tetrabutylammonium bromide, amount of
potassium hydroxide, amount of water, organic solvents, and
temperature on the conversion of the reactant. The kinetics are
well described by a pseudo-first-order rate law. A rational
explanation of the results was made. Products of high purity
were also obtained using pressurized column chromatography.
“…3 These kinds of natural opioid alkaloids are known to function in the central nervous system (CNS) by strong binding to G‐protein‐coupled receptors (GPR) 4. The detailed mechanism of the interactions between GPR and binding ligands in the CNS remains elusive, though a variety of chemical modifications of such opioid alkaloids are necessary not only for drug addiction treatments but also for potential remedies for neurological disorders such as Alzheimer’s and Parkinson’s disease, as well as depression and schizophrenia 5…”
Section: Methodsmentioning
confidence: 99%
“…Under the optimized reaction conditions, we tested cycloisomerization reactions with a series of VBCs ( Table 2). The 7-cyclopropylbicycloA C H T U N G T R E N N U N G [4.1.0]hept-4-ene derivatives used in this study (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) were readily obtained by PtCl 2 -catalyzed cycloisomerization of the corresponding enynes (Scheme 2). [9] Various 7-cyclopropyl-6-aryl-3-azabicycloA C H T U N G T R E N N U N G [4.1.0]hept-4-ene derivatives with a substituent at the para-position of 6-aryl group could participate in the reaction (entries 2-6).…”
Important class: Nitrogen‐containing heterobicycles are an important structural motif ubiquitous in natural alkaloids. We found that azabicyclo[3.2.2]nona‐2,8‐dienes can be synthesized from vinyl bicyclopropropyl derivatives in the presence of a RhI catalyst (see scheme). Syntheses of such compounds and an investigation into the reaction mechanism through DFT calculations are presented.
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