Stereoselective Synthesis of [1]Benzopyrano[4,3-b]pyrrol-4(3H)-ones through Cycloadditions of Azomethine Ylides with α,β-Unsaturated Esters
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چکیده
منابع مشابه
Enantioselective dearomative [3 + 2] cycloadditions of indoles with azomethine ylides derived from alanine imino esters†
Catalytic, enantioselective [3 + 2] cycloadditions of azomethine ylides derived from alanine imino esters with 3-nitroindoles are reported. The dearomative cycloaddition reactions occur in the presence of a catalyst generated in situ from Cu(OTf)2 and (R)-Difluorphos to form exo’-pyrroloindoline cycloadducts and establish four contiguous stereogenic centers, two of which are fully substituted. ...
متن کاملCatalytic Enantioselective 1,3-Dipolar Cycloadditions of Azomethine Ylides for Biology-Oriented Synthesis
Cycloaddition reactions are among the most powerful methods for the synthesis of complex compounds. In particular, the development and application of the 1,3-dipolar cycloaddition, an important member of this reaction class, has grown immensely due to its powerful ability to efficiently build various five-membered heterocycles. Azomethine ylides are commonly used as dipoles for the synthesis of...
متن کامل1,3-dipolar cycloadditions from tricyclic hemiaminals. Synthesis of the quinocarcin core through catalyst-free generation of azomethine ylides.
The generation of azomethine ylides from the readily accessible hemiaminals 3 and 8 or from iminium salt 10 was studied. Compounds 8 gave anti- and syn-cycloadducts containing the quinocarcin core through a catalyst-free dehydration process.
متن کاملUnstabilized azomethine ylides for the stereoselective synthesis of substituted piperidines, tropanes, and azabicyclo[3.1.0] systems.
Acid treatment of densely substituted 2-silyl-1,2-dihydropyridines provides a new and convenient entry to reactive azomethine ylides that can (1) be protonated and reduced with high stereoselectivity to give piperidines, (2) participate in [3 + 2] dipolar cycloaddition to give tropanes, and (3) undergo a Nazarov-like 6-π electrocyclization that upon reduction give 2-azabicyclo[3.1.0] systems.
متن کاملSynthesis of Some New 3-Pyrrolidinylquinoline Derivatives via 1,3-Dipolar Cycloaddition of Stabilized Azomethine Ylides to Quinolinyl ,- Unsaturated Ketones
N-Metallated azomethine ylide generated from methyl (E)-N-benzylideneglycinate, LiBr and triethylamine underwent cycloaddition to quinolyl , -unsaturated ketones with excellent diastereoselectivity to afford new functionalised 3-pyrrolidinylquinoline derivatives.
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ژورنال
عنوان ژورنال: Bulletin of the Chemical Society of Japan
سال: 1989
ISSN: 0009-2673,1348-0634
DOI: 10.1246/bcsj.62.808