An efficient formal [4+2] annulation between 2-benzothiazolimines and allenoates mediated by an amino acid-derived bifunctional phosphonium salt catalyst is developed. This protocol provides a new and facile synthetic approach to create a broad range of isothiourea-based benzothiazolopyrimidine derivatives under mild reaction conditions with high isolated yields and excellent diastereo- and enantioselectivities.

中文翻译：

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双功能functional盐体系下苯并噻唑并嘧啶的不对称合成具有高催化效率和立体选择性。

建立了由氨基酸衍生的双官能phospho盐催化剂介导的2-苯并噻唑啉和脲基甲酸酯之间的有效形式[4 + 2]环。该方案提供了一种新的简便的合成方法，可以在温和的反应条件下，以高分离产率，优异的非对映和对映选择性，制备出多种基于异硫脲的苯并噻唑并嘧啶衍生物。