Base assisted divergent reactivity of isatins and allenoates has been achieved, which afforded diastereoselective spirofuran oxindoles and γ-functionalized allenoates. The DBU mediated Morita–Baylis–Hillman (MBH) reaction followed by the cascade annulation through the stabilized β-ammonium enolate intermediate led to the spiro-framework, wherein DABCO furnished the γ-functionalized allenoates. The protocol offers access to biologically relevant functionalized oxindole scaffolds with an excellent substrate scope under mild reaction conditions.

中文翻译：

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通过碱实现的非对映选择性螺呋喃呋喃吲哚和γ-官能化的烯酸酯的访问

已经实现了靛红和脲基甲酸酯的碱辅助发散反应性，这提供了非对映选择性的螺呋喃氧吲哚和γ-官能化的脲基甲酸酯。DBU介导的Morita-Baylis-Hillman（MBH）反应，然后通过稳定的β-铵烯醇盐中间体进行级联成环，形成了螺骨架，其中DABCO提供了γ-官能化的烯酸酯。该协议提供了在温和的反应条件下具有出色的底物范围的生物学相关的功能化羟吲哚支架的访问途径。