Electron Transfer Reactions in Organic Chemistry. XXI. New Catalysts for the Diels--Alder Dimerization of 1,3-Cyclohexadiene: Brönsted, Lewis and Redox Catalysts.
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چکیده
منابع مشابه
Carbocations as Lewis acid catalysts in Diels-Alder and Michael addition reactions.
In general, Lewis acid catalysts are metal-based compounds that owe their reactivity to a low-lying empty orbital. However, one potential Lewis acid that has received negligible attention as a catalyst is the carbocation. We have demonstrated the potential of the carbocation as a highly powerful Lewis acid catalyst for organic reactions. The stable and easily available triphenylmethyl (trityl) ...
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A reactivity difference based on the position of substituents on cyclohexa-1,3- diene was observed for the title reaction. The effect of water as solvent was more distinct for 1-methyl-4-isopropylcyclohexa-1,3-diene than for 2-methyl-5-isopropylcyclohexa- 1,3-diene or non-substituted cyclohexa-1,3-diene. The effect of NaCl (salting-out) and guanidium chloride (salting-in) was also large for 1-m...
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An ene-yne cross metathesis of silyl substituted alkynes and alkenes followed by a Diels-Alder reaction of the metathesis product 2-silyl-1,3-dienes has been developed. The dienes thus prepared in situ were shown to participate in highly diastereoselective Diels-Alder reactions. In one case the silicon substituted Diels-Alder cycloadduct was subsequently used without isolation and purification ...
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ژورنال
عنوان ژورنال: Acta Chemica Scandinavica
سال: 1992
ISSN: 0904-213X
DOI: 10.3891/acta.chem.scand.46-1005