据报道,有一种新的策略可以通过吡啶甲酰胺辅助的钯催化的C–H键活化反应从脂肪族胺中构建复杂的多环含氮杂环。该反应显示出广泛的底物范围,可用于合成各种氮杂双环支架,包括氮杂环丁烷和托烷类生物碱。该方法在天然存在的(-)-顺式-二甲基乙胺中的应用,这是前所未有的碳-碳键活化,其中涉及的电子对引发了环钯片段的分子内“ S N 2样”置换。第三中心,描述。
Highly Efficient Syntheses of Azetidines, Pyrrolidines, and Indolines via Palladium Catalyzed Intramolecular Amination of C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H Bonds at γ and δ Positions
palladium-catalyzed intramolecular amination of C-H bonds at the γ and δ positions of picolinamide (PA) protected amine substrates. These methods feature relatively a low catalyst loading, use of inexpensive reagents, and convenient operating conditions. Their selectivities are predictable. These methods highlight the use of unactivated C-H bond, especially the C(sp(3))-H bond of methyl groups, as functional