C(sp<sup>3</sup>)–H dehydrogenation and C(sp<sup>2</sup>)–H alkoxy carbonylation of inactivated cyclic amines towards functionalized N-heterocycles
作者:Yan He、Fang Wang、Xinying Zhang、Xuesen Fan
DOI:10.1039/c6cc10227a
日期:——
A novel and efficient synthesis of tetrahydropyridine-, dihydropyrrole-, and tetrahydroazepine-3-carboxylates via cascade reactions of cyclic amines with CO and alcohols is presented. To our knowledge, this should be the first example in which functionalized N-heterocycles were prepared through Pd-catalyzed C(sp3)-H dehydrogenation and C(sp2)-H carbonylation of cyclic amines.
The conversion of β-amido esters to β-enamino esters is an indispensable step for some synthetic approaches to alkaloids and related medicines. Known methods for such transformation are not only stepwise, but also proceed with low atom-efficiency. Herein, we report a direct and versatile approach that features the Ir-catalyzed chemoselective reduction of β-amido esters with 1,1,3,3-tetramethyldisiloxane
对于某些生物碱和相关药物的合成方法,β-酰胺基酯向β-烯氨基酯的转化是必不可少的步骤。用于这种转化的已知方法不仅是逐步的,而且以低原子效率进行。本文中,我们报道了一种直接且通用的方法,其特征在于用1,1,3,3-四甲基二硅氧烷(TMDS)进行Ir催化的β-酰胺基酯的化学选择性还原。另外,在某些脂环族β-烯胺酯的13 C NMR光谱中观察到缺少某些信号。这揭示了文献中长期存在但被忽略的现象。