Enantioselective gold catalyzed dearomative [2+2]-cycloaddition between indoles and allenamides.
نویسندگان
چکیده
The highly enantioselective synthesis of densely functionalized 2,3-indoline-cyclobutanes by means of chiral gold catalysis is presented. Intermolecular formal [2+2]-cycloaddition reactions between substituted indoles and allenamides enabled direct access to methylenecyclobutane-fused indolines, featuring two consecutive quaternary stereogenic centers with excellent stereochemical control (dr > 20 : 1, ee up to 99%).
منابع مشابه
Gold-catalyzed synthesis of tetrahydrocarbazole derivatives through an intermolecular cycloaddition of vinyl indoles and N-allenamides.
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A Ni(ClO4)2-catalyzed enantioselective [2 + 2] cycloaddition of N-allenamides with cyclic N-sulfonylketimines was developed, which regioselectively occurred at the proximal CC bonds of the N-allenamides. Broad substrate scope of N-allenamides and cyclic N-sulfonylketimines was observed. A range of fused polysubstituted azetidines bearing quaternary stereocenters were afforded in good yields and...
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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 کاملEnantioselective [2 + 2] cycloaddition of N-allenamides with cyclic N-sulfonylketimines: access to polysubstituted azetidines bearing quaternary stereocenters† †Electronic supplementary information (ESI) available: Experimental procedure, characterization data for all the new compounds, and chiral HPLC spectra for the products. CCDC 1495550. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc05450a Click here for additional data file. Click here for additional data file.
A Ni(ClO4)2-catalyzed enantioselective [2 + 2] cycloaddition ofN-allenamides with cyclicN-sulfonylketimines was developed, which regioselectively occurred at the proximal C]C bonds of the N-allenamides. Broad substrate scope of N-allenamides and cyclic N-sulfonylketimines was observed. A range of fused polysubstituted azetidines bearing quaternary stereocenters were afforded in good yields and ...
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ورودعنوان ژورنال:
- Chemical communications
دوره 51 12 شماره
صفحات -
تاریخ انتشار 2015