(BXT) as an electrophile under room temperature conditions. The reaction tolerates a variety of electron-rich arenes and heteroarenes to afford the corresponding arylbenziodoxoles in moderate to good yields. The reaction can also be performed mechanochemically by grinding a mixture of solid arenes and BXT undersolvent-freeconditions. The arylbenziodoxoles can be used for various C–C and C–heteroatom
Nickel-Catalyzed Dearomative Arylboration of Indoles: Regioselective Synthesis of C2- and C3-Borylated Indolines
作者:Grace L. Trammel、Rositha Kuniyil、Phillip F. Crook、Peng Liu、M. Kevin Brown
DOI:10.1021/jacs.1c05902
日期:2021.10.13
the C2- or C3-positions. Synthetically useful C2- and C3-borylated indolines can be accessed through a simplechange in N-protecting group in high regio- and diastereoselectivities (up to >40:1 rr and >40:1 dr) from readily available starting materials. Additionally, the origin of regioselectivity was explored experimentally and computationally to uncover the remarkable interplay between carbonyl orientation
An efficient synthesis of N-acetyl-2-substituted indole derivatives via direct intramolecular hydroamination of N-acetyl-2-alkynylaniline derivatives was developed. The reaction could be applied to a wide range of substrates employing only 1–2 mol% of PtCl4 as the catalyst to furnish the desired indole products in moderate to excellent yields. The current protocol is efficient, reliable and scalable
The Pd-catalyzed Suzuki–Miyaura cross-coupling of alkyl- and fluoroalkyl(diphenyl)sulfonium triflates with arylboronicacids was compared. The fluorine substitution on the alkyl groups of [Ph2SR][OTf] had a big influence on the reaction. Perfluoroalkyl(diphenyl)sulfonium triflates (2b–d) were unsuccessful participants in the Pd-catalyzed phenylation of arylboronicacid under the standard conditions because
比较了Pd催化的三氟甲基磺酸烷基酯和氟代烷基(二苯基)ulf与芳基硼酸的Suzuki-Miyaura交叉偶联。[Ph 2 SR] [OTf]烷基上的氟取代对反应有很大影响。在标准条件下,全氟烷基(二苯基)ulf三氟甲磺酸酯(2b–d)未能成功地参与Pd催化的芳基硼酸的苯基化反应,因为长链全氟烷基具有很强的负电性,而是经S R fn键断裂。多氟烷基三苯二氟es(2f–h)与芳基硼酸反应,由于de盐的去质子化和β-F消除的趋势,以非常低的收率得到苯基化产物。最终,发现(2,2,2-三氟乙基)三氟甲磺酸二苯基s(2e),三氟甲磺酸甲基或乙基(二苯基)i(2i或2j)和三氟甲磺酸三苯基s(2m)是比其他测试过的苯基硫salts盐更有效的试剂钯催化的苯基化反应,在温和条件下可提供更高的所需产物收率。
Redox-Neutral Photocatalytic C−H Carboxylation of Arenes and Styrenes with CO2
作者:Matthias Schmalzbauer、Thomas D. Svejstrup、Florian Fricke、Peter Brandt、Magnus J. Johansson、Giulia Bergonzini、Burkhard König
DOI:10.1016/j.chempr.2020.08.022
日期:2020.10
Carbondioxide (CO2) is an attractive one-carbon (C1) building block in terms of sustainability and abundance. However, its low reactivity limits applications in organic synthesis as typically high-energy reagents are required to drive transformations. Here, we present a redox-neutral C─H carboxylation of arenes and styrenes using a photocatalytic approach. Upon blue-light excitation, the anthrolate