本文公开了通过 S E Ar(亲电芳族取代)型反应对N-嘧啶基(杂)芳烃进行区域选择性对-C-H 卤化。S E Ar 型反应已用于二氢吲哚的 C5-溴化(对位选择性)与N-溴代琥珀酰亚胺在无金属和无添加剂的条件下具有良好至极好的收率。所开发的方法也适用于碘化和具有挑战性的氯化。嘧啶基被确定为反应性调节剂,它也控制区域选择性。本方法也适用于苯胺、吡啶、吲哚、羟吲哚、吡唑、四氢喹啉、异喹啉和咔唑的选择性卤化。Fukui 亲核性和自然电荷图等 DFT 研究也支持观察到的p-选择性。标题化合物后官能化为相应的芳基化、烯化和二卤化产物是通过一锅两步的方式实现的。还对药物/天然分子(哈明、依托考昔、可乐定和氯唑沙宗)进行了后期 C-H 溴化,以证明所开发方案的适用性。
Air‐Stable Carbonyl(pentamethylcyclopentadienyl)cobalt Diiodide Complex as a Precursor for Cationic (Pentamethylcyclopentadienyl)cobalt(III) Catalysis: Application for Directed C‐2 Selective CH Amidation of Indoles
dienyl)cobalt diiodide complex [Cp*Co(CO)I2] was successfully utilized as the precursor of a cationic cobalt(III) active catalyst for directed CH bond functionalization. The complex Cp*Co(CO)I2 (2.5–1.25 mol%), in combination with silver hexafluoroantimonate (AgSbF6) and potassium acetate (KOAc), efficiently catalyzed the directed C‐2 selective amidation of indoles with sulfonyl azides, and the corresponding
A rhodium-catalyzed C–H functionalization with activated amides by decarbonylation has been developed. Notably, this is the first C–H arylation employing N-acylsaccharins as coupling partners to give biaryls in good to excellent yields. The highlight of the work is the high tolerance of functional groups such as formyl, ester, and vinyl and the use of a removable directing group.
A direct C-2 methylation reaction of indoles bearing a readily removable N-2-pyrimidyl moiety as a site-specific directing group has been developed with a palladium catalyst. This reaction relied on the use of KF to promote efficient methylation. A moderate to good yield was achieved in a range of indole substrates.
Iridium(III)-Catalyzed Regioselective Carbenoid Insertion C-H Alkylation by α-Diazotized Meldrum's Acid
作者:Honggui Lv、William L. Xu、Kunhua Lin、Jingjing Shi、Wei Yi
DOI:10.1002/ejoc.201601212
日期:2016.12
straightforward protocol for IrIII-catalyzed regioselective carbenoid insertion C–H alkylationmediated by α-diazotized Meldrum's acid was developed. The assistance of external additives and oxidants was not needed, and the developed IrIII catalysis proceeds in a highly efficient manner (e.g., mild reaction conditions, short reaction times and excellent regioselectivity) and demonstrates good compatibility