CAL-B (Candida antarcticalipaseB) immobilized on an acrylic resin (Novozyme® 435) smoothly catalyzes the aminolysis of methyl esters with propargyl amine furnishing propargyl amides. In the same reaction vessel these propargyl derivatives are consecutively transformed into amide ligated 1,2,3-triazoles in a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction in good to excellent yields
Consecutive three-component synthesis of (hetero)arylated propargyl amides by chemoenzymatic aminolysis–Sonogashira coupling sequence
作者:Sidra Hassan、Anja Ullrich、Thomas J. J. Müller
DOI:10.1039/c4ob02386b
日期:——
A novel chemoenzymatic three-componentsynthesis of (hetero)arylated propargyl amides in good yields based upon Novozyme® 435 (Candida antarctica lipase B (CAL-B)) catalyzed aminolysis of methyl carboxylates followed by Sonogashira coupling with (hetero)aryliodides in a consecutive one-pot fashion has been presented. This efficient methodology can be readily concatenated with a CuAAC (Cu catalyzed
click-and-release reactions are powerful tools for chemical biology, allowing, for example, the selective release of drugs in biological media, including inside animals. Here, we developed two new families of iminosydnone mesoionic reactants that allow a bioorthogonal release of electrophilic species under physiological conditions. Their synthesis and reactivities as dipoles in cycloadditionreactions with strained
生物正交点击和释放反应是化学生物学的强大工具,例如,允许在生物介质(包括动物体内)中选择性释放药物。在这里,我们开发了两个新的 iminosydnone 中离子反应物家族,它们允许在生理条件下生物正交释放亲电物质。已经详细研究了它们在与紧张炔烃的环加成反应中作为偶极子的合成和反应性。尽管通过实验证明了 pH 值对反应动力学的影响,但理论计算表明,与先前描述的亚氨基糖酮相比,新设计的偶极子显示出降低的共振稳定能量,这解释了它们具有更高的反应性。这些中离子化合物在生理条件下与环炔烃顺利反应,无铜反应条件与释放的烷基异氰酸酯或芳基异氰酸酯一起形成点击吡唑产物。速率常数高达 1000 M–1 s –1,这种点击和释放反应是迄今为止描述的最快的反应之一,代表了第一个允许在活细胞内释放异氰酸酯亲电子试剂的生物正交过程,为化学生物学提供了有趣的视角。