摘要：

A new DBU-catalyzed formal [4+2] cycloaddition between ortho-hydroxyphenyl-substituted para-quinone methides and electron-deficient dienophiles including 3-methyleneoxindoles and 2-aryldeneindene-1,3-diones was established. A wide range of functionalized spiro[chromane-3,3′-indolines] and spiro[chromane-3,2′-indenes] were successfully synthesized in good yields and with high diastereoselectivity. The features of the reaction included readily available substrates, mild reaction conditions, convenient methodology and good functional group tolerance.Spirooxindoles were diastereoselectively synthezied via DBU catalyzed formal [4+2] cycloaddition of ortho-hydroxyphenyl-substituted para-quinone methides and 3-methyleneoxindoles and 2-aryldeneindene-1,3-diones.Image 1

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