饱和杂环存在于许多治疗剂和生物活性天然产物中,并且在许多医药和农化化合物库中含量丰富。为了获得新的化学空间和功能,人们开发了许多在这些结构外围进行功能化的方法。已知的用于重构其核心框架的方法相对较少。在此,我们描述了可见光介导的α-酰化饱和杂环的环收缩。这种非常规的转化与传统的环收缩正交,挑战了杂环多样化的范式,包括哌啶、吗啉、噻烷、四氢吡喃和四氢异喹啉衍生物。这种 Norrish II 型变体的成功取决于特定化学环境中光反应酮基团之间的反应性差异。该策略应用于药物衍生物、肽和糖的后期重塑。
A novel Ni/photoredox-catalyzed acylation of aliphatic substrates, including simple alkanes and dialkyl ethers, has been developed. The method combines C–N bond activation of amides with a radical relay mechanism involving hydrogen-atom transfer. The protocol is operationally simple, employs bench-stable N-acyl imides as acyl-transfer reagents, and permits facile access to alkyl ketones under very
Direct coupling of ethers and acylhalides was promoted by a binary catalytic system comprising an Ir-based photocatalyst and a Ni complex under blue-light irradiation. Photocatalysts with high triplet energy directed the catalysis, and the reaction likely proceeded by triplet–triplet energy transfer from the excited photocatalysts. Chlorine radicals generated from an excited Ni complex bearing a Ni–Cl
Carbene‐Catalyzed Intermolecular Dehydrogenative Coupling of Aldehydes with C(sp<sup>3</sup>)−H Bonds
作者:Fen Su、Juan Zou、Xiaokang Lv、Fengfei Lu、Yijie Long、Kun Tang、Benpeng Li、Huifang Chai、Xingxing Wu、Yonggui Robin Chi
DOI:10.1002/anie.202303388
日期:2023.6.5
An NHC-catalyzed intermolecular dehydrogenativecoupling of aldehyde with ether, amine or benzylic C(sp3)−H bonds is disclosed via metal- and light-free radicalpathways.
Photoinduced cerium-catalyzed C–H acylation of unactivated alkanes
作者:Jing Cao、Joshua L. Zhu、Karl A. Scheidt
DOI:10.1039/d3sc05162e
日期:——
Ketones are ubiquitous motifs in the realm of pharmaceuticals and natural products.
在医药和天然产品领域,酮是无处不在的主题。
Photomediated ring contraction of saturated heterocycles
作者:Justin Jurczyk、Michaelyn C. Lux、Donovon Adpressa、Sojung F. Kim、Yu-hong Lam、Charles S. Yeung、Richmond Sarpong
DOI:10.1126/science.abi7183
日期:2021.8.27
visible light–mediated ring contraction of α-acylated saturatedheterocycles. This unconventional transformation is orthogonal to traditional ring contractions, challenging the paradigm for diversification of heterocycles including piperidine, morpholine, thiane, tetrahydropyran, and tetrahydroisoquinoline derivatives. The success of this Norrish type II variant rests on reactivity differences between
饱和杂环存在于许多治疗剂和生物活性天然产物中,并且在许多医药和农化化合物库中含量丰富。为了获得新的化学空间和功能,人们开发了许多在这些结构外围进行功能化的方法。已知的用于重构其核心框架的方法相对较少。在此,我们描述了可见光介导的α-酰化饱和杂环的环收缩。这种非常规的转化与传统的环收缩正交,挑战了杂环多样化的范式,包括哌啶、吗啉、噻烷、四氢吡喃和四氢异喹啉衍生物。这种 Norrish II 型变体的成功取决于特定化学环境中光反应酮基团之间的反应性差异。该策略应用于药物衍生物、肽和糖的后期重塑。