已开发了在存在石墨化碳氮化物(gC 3 N 4)的情况下,进行甲硅烷基胺和α-氨基酸的光氧化活化的方案,以进行脱甲硅基和脱羧的加成,烯丙基化和杂芳基化。该方法具有广泛的范围,并以高收率提供了所需的产品。gC 3 N 4催化系统的非均质性质使其易于回收和循环利用,并且可以多次使用而不会损失活性。光氧化还原催化的反应也可以以连续的光流方式进行并按比例放大至克级。因此,稳定且容易获得的聚合物gC 3 N 4 提供了均相光敏剂的替代品,用于生成有价值的自由基中间体,用于合成和催化。
Visible-Light Photoredox-Catalyzed Giese Reaction: Decarboxylative Addition of Amino Acid Derived α-Amino Radicals to Electron-Deficient Olefins
作者:Anthony Millet、Quentin Lefebvre、Magnus Rueping
DOI:10.1002/chem.201602257
日期:2016.9.12
A tin‐ and halide‐free, visible‐light photoredox‐catalyzed Giese reaction was developed. Primary and secondary α‐amino radicals were generated readily from aminoacids in the presence of catalytic amounts of an iridium photocatalyst. The reactivity of the α‐amino radicals has been evaluated for the functionalization of a variety of activated olefins.
Minimization of Back‐Electron Transfer Enables the Elusive sp
<sup>3</sup>
C−H Functionalization of Secondary Anilines
作者:Huaibo Zhao、Daniele Leonori
DOI:10.1002/anie.202100051
日期:2021.3.29
Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N‐Dialkyl‐derivatives enable radicalgenerationα to the N‐atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back‐electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence
苯胺是光诱导电子转移中最常用的一类底物。 N,N-二烷基衍生物能够通过氧化然后去质子化使 N 原子产生自由基 α。然而,由于快速反电子转移(BET),这种方法对于单取代苯胺来说难以捉摸。在这里,我们证明了在外源烷基胺存在的情况下使用光氧化还原催化可以最大限度地减少 BET。这种方法协同帮助苯胺 SET 氧化,然后加速随后的去质子化。通过这种方式,现在可以生成 α-苯胺烷基自由基,并且这些物质可以在一般意义上用于实现不同的 sp 3 C−H 官能化。
Heterogeneous Visible-Light Photoredox Catalysis with Graphitic Carbon Nitride for α-Aminoalkyl Radical Additions, Allylations, and Heteroarylations
desilylative and decarboxylative additions, allylations, and heteroarylations in the presence of graphitic carbon nitride (g-C3N4) was developed. The procedure has broad scope and provides the desired products in high yields. The heterogeneous nature of the g-C3N4 catalytic system enables easy recovery and recycling as well as the use in multiple runs without loss of activity. The photoredox catalyzed reactions
已开发了在存在石墨化碳氮化物(gC 3 N 4)的情况下,进行甲硅烷基胺和α-氨基酸的光氧化活化的方案,以进行脱甲硅基和脱羧的加成,烯丙基化和杂芳基化。该方法具有广泛的范围,并以高收率提供了所需的产品。gC 3 N 4催化系统的非均质性质使其易于回收和循环利用,并且可以多次使用而不会损失活性。光氧化还原催化的反应也可以以连续的光流方式进行并按比例放大至克级。因此,稳定且容易获得的聚合物gC 3 N 4 提供了均相光敏剂的替代品,用于生成有价值的自由基中间体,用于合成和催化。