C–H Alkylation of Aldehydes by Merging TBADT Hydrogen Atom Transfer with Nickel Catalysis,Organic Letters

当前位置： X-MOL 学术 › Org. Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

C–H Alkylation of Aldehydes by Merging TBADT Hydrogen Atom Transfer with Nickel Catalysis
Organic Letters ( IF 4.9 ) Pub Date : 2021-06-25 , DOI: 10.1021/acs.orglett.1c01716
Vetrivelan Murugesan ₁ , Anirban Ganguly ₁ , Ardra Karthika ₁ , Ramesh Rasappan ₁

Affiliation

Catalyst controlled site-selective C–H functionalization is a challenging but powerful tool in organic synthesis. Polarity-matched and sterically controlled hydrogen atom transfer (HAT) provides an excellent opportunity for site-selective functionalization. As such, the dual Ni/photoredox system was successfully employed to generate acyl radicals from aldehydes via selective formyl C–H activation and subsequently cross-coupled to generate ketones, a ubiquitous structural motif present in the vast majority of natural and bioactive molecules. However, only a handful of examples that are constrained to the use of aryl halides are developed. Given the wide availability of amines, we developed a cross-coupling reaction via C–N bond cleavage using the economic nickel and TBADT catalyst for the first time. A range of alkyl and aryl aldehydes were cross-coupled with benzylic and allylic pyridinium salts to afford ketones with a broad spectrum of functional group tolerance. High regioselectivity toward formyl C–H bonds even in the presence of α-methylene carbonyl or α-amino/oxy methylene was obtained.

中文翻译：

通过将 TBADT 氢原子转移与镍催化合并进行醛的 C-H 烷基化

催化剂控制的位点选择性 C-H 功能化是有机合成中具有挑战性但功能强大的工具。极性匹配和空间控制的氢原子转移 (HAT) 为位点选择性功能化提供了极好的机会。因此，双镍/光氧化还原系统成功地用于通过选择性甲酰基 C-H 活化从醛生成酰基自由基，随后交叉偶联生成酮，这是绝大多数天然和生物活性分子中普遍存在的结构基序。然而，仅开发了少数限制使用芳基卤化物的例子。鉴于胺的广泛可用性，我们首次使用经济的镍和 TBADT 催化剂通过 C-N 键断裂开发了交叉偶联反应。一系列烷基和芳基醛与苄基和烯丙基吡啶盐交叉偶联，以提供具有广谱官能团耐受性的酮。即使在α-亚甲基羰基或α-氨基/氧基亚甲基存在下，也获得了对甲酰基C-H键的高区域选择性。

更新日期：2021-07-16

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南