Catalytic intermolecular linear allylic C-H amination via heterobimetallic catalysis
Catalytic intermolecular linear allylic C-H amination via heterobimetallic catalysis
复制标题
DOI：
10.1021/ja710206u
复制
发表时间：
2008-03-19
影响因子：
15
通讯作者：
White, M. Christina
中科院分区：
文献类型：
--
作者：
Reed, Sean A.;White, M. Christina
报道了一种新的杂环钯亚砜/（salen）Cr（III）Cl催化的烯丙基C-H胺化反应（LAA）。该反应将密集官能化的M-烯烃底物（如果当量）直接转化为线性（E）-烯丙基氨基甲酸酯，具有良好的产率和突出的区域选择性和立体选择性（>20：1）。手性双-高烯丙基和高烯丙基氧、氮和碳取代的α-烯烃进行烯丙基C-H胺化，具有良好的产率、优异的选择性和对映体纯度的无侵蚀。还证明了（E）-烯丙基氨基甲酸酯的简化路线，其可以进一步加工成医学和生物学相关的烯丙基胺。有价值的N-15-标记的烯丙基胺可以通过使用容易获得的N-15-（甲氧羰基）-对甲苯磺酰胺亲核试剂在合成路线的后期直接从allo部分产生。有证据表明，该反应通过一个heterodynamic机制进行，其中Pd/亚砜介导烯丙基C-H裂解，形成一个pi-烯丙基Pd中间体，和（salen）Cr（III）Cl/BQ一起工作，以促进与氮亲核试剂的官能化。
A novel heterobimetallic Pd(II)sulfoxide/(salen)Cr(III)Cl-catalyzed intermolecular linear allylic C-H amination (LAA) is reported. This reaction directly converts densely functionalized M-olefin substrates If equiv) to linear (E)-allylic carbamates with good yields and outstanding regio- and stereoselectivities (>20:1). Chiral bis-homoallylic and homoallylic oxygen, nitrogen, and carbon substituted alpha-olefins undergo allylic C-H amination with good yields, excellent selectivities, and no erosion in enantiomeric purity. Streamlined routes to (E)-allylic carbamates that can be further elaborated to medicinally and biologically relevant alylic amines are also demonstrated. Valuable N-15-labeled allylic amines may be generated directly from allo moieties at late stages of synthetic routes by using the readily available N-15-(methoxycarbonyl)-p-toluenesulfonamide nucleophile. Evidence is provided that this reaction proceeds via a heterobimetallic mechanism where Pd/sulfoxide mediates allylic C-H cleavage to form a pi-allyl Pd intermediate, and (salen)Cr(III)Cl/BQ work together to promote functionalization with the nitrogen nucleophile.