An unexpected role of a trace amount of water in catalyzing proton transfer in phosphine-catalyzed (3 + 2) cycloaddition of allenoates and alkenes.
نویسندگان
چکیده
Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking UniVersity, Beijing 100871, China, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China, and Key Laboratory of Organic Synthesis of Jiangsu ProVince, Department of Chemistry and Chemical Engineering, Suzhou UniVersity, Suzhou 215006, China
منابع مشابه
Phosphine-containing Lewis base catalyzed cyclization of benzofuranone type electron-deficient alkenes with allenoates: a facile synthesis of spirocyclic benzofuranones.
A regioselective [3 + 2] cycloaddition of benzofuranone type active olefins with allenoates catalyzed by trivalent phosphines has been developed, which provided an easy access to enriched functionalized spirocyclic benzofuranones. The reactions accommodated a number of benzofuranone type electron-deficient olefins and allenoates to give the desired 3-spirocyclopentane benzofuran-2-ones or 2-spi...
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The triphenylphosphine-catalyzed formal [3 + 2] cycloaddition of allenoates and trifluoromethylketones was realized to give the corresponding dihydrofurans in good yields with excellent γ-regioselectivities. Hydrogenation of the dihydrofurans gave 2,4,4-trisubstituted tetrahydrofurans in good yields with exclusive cis-selectivities.
متن کاملPhosphine-catalyzed [3+2] annulation of α-substituted allenoates with ester-activated α,β-unsaturated imines: a novel variation of the Lu [3+2] cycloaddition reaction.
A phosphine-catalyzed [3+2] annulation reaction of α-substituted allenoates with ester-activated α,β-unsaturated imines is reported, which provides new and efficient access to highly functionalized cyclopentenes bearing one all-carbon quaternary center. This reaction also expands the scope of the famous Lu [3+2] cycloaddition reaction.
متن کاملPhosphine-Catalyzed [2 + 4] Annulation of Allenoates with Thiazolone-Derived Alkenes: Synthesis of Functionalized 6,7-Dihydro-5H-pyrano[2,3-d]thiazoles.
Phosphine-catalyzed [2 + 4] annulation of allenoates with thiazolone-derived alkenes has been achieved under mild conditions, giving biologically important 6,7-dihydro-5H-pyrano[2,3-d]thiazole derivatives in high to excellent yields. With the use of Kwon's phosphine as the chiral catalyst, optically active products were obtained in good yields with excellent enantioselectivities.
متن کاملPhosphine-catalyzed [4+2] annulations of 2-alkylallenoates and olefins: synthesis of multisubstituted cyclohexenes.
From our investigations on phosphine-catalyzed [4+2] annulations between α-alkyl allenoates and activated olefins for the synthesis of cyclohexenes, we discovered a hexamethylphosphorous triamide (HMPT)-catalyzed [4+2] reaction between α-alkyl allenoates 1 and arylidene malonates or arylidene cyanoacetates 2 that provides highly functionalized cyclohexenes 3 and 4 in synthetically useful yields...
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عنوان ژورنال:
- Journal of the American Chemical Society
دوره 129 12 شماره
صفحات -
تاریخ انتشار 2007