effective direct hydrogen‐atom transfer catalyst for C−H activation. Using the alkylation of C−Hbonds with electron‐deficient alkenes as a model study revealed an extremely broad substrate scope, enabling easy access to a variety of important synthons. This eosin Y‐based photocatalytic hydrogen‐atom transfer strategy is promising for diverse functionalization of a wide range of native C−Hbonds in a green
products. Its light-absorption properties make it useful for the design of functional molecules. However, versatile synthesis methods have not yet been reported. In this report, we present a versatile synthetic method for pseudoindoxyls using the direct S0 → Tn transition under visiblelight irradiation. We also discuss the application of pseudoindoxyls as photocatalysts.
假吲哚酚是在各种天然产物中发现的部分骨架。其光吸收特性使其可用于功能分子的设计。然而,通用的合成方法尚未见报道。在本报告中,我们提出了一种在可见光照射下利用直接 S 0 → T n跃迁合成假吲哚酚的通用方法。我们还讨论了假吲哚酚作为光催化剂的应用。
δ-Nitroalkanols as precursors for the one-pot synthesis of substituted tetrahydrofurans
作者:Roberto Ballini、Dennis Fiorini、Maria Victoria Gil、Alessandro Palmieri、Emilio Román、José Antonio Serrano
DOI:10.1016/s0040-4039(03)00461-1
日期:2003.3
DBU catalyses the one-pot Michael addition of nitroalkanes to 1,4-dienone derivatives, elimination of nitrous acid, then intramolecular conjugate addition-ring closure to allow the direct formation of a variety of tetrahydrofurans. (C) 2003 Elsevier Science Ltd. All rights reserved.
Titania-Promoted Carboxylic Acid Alkylations of Alkenes and Cascade Addition–Cyclizations
作者:David W. Manley、Roy T. McBurney、Phillip Miller、John C. Walton、Andrew Mills、Christopher O’Rourke
DOI:10.1021/jo4027929
日期:2014.2.7
electron-deficient alkenes. The efficiency of alkylation varied appreciably with substituents in the carboxylic acids. The reactions of aryloxyacetic acids with maleimides resulted in a cascade process in which a pyrrolochromene derivative accompanied the alkylated succinimide. The selectivity for one or other of these products could be tuned to some extent by employing the photoredoxcatalyst under different
使用 TiO 2 的光化学反应和羧酸在干燥厌氧条件下导致几种类型的 C-C 键形成过程与缺电子烯烃。烷基化的效率随羧酸中的取代基而显着变化。芳氧基乙酸与马来酰亚胺的反应导致了一个级联过程,其中吡咯并色烯衍生物伴随着烷基化的琥珀酰亚胺。通过在不同条件下使用光氧化还原催化剂,可以在一定程度上调整这些产品中的一种或其他产品的选择性。通过包含 2-烯基、2-芳基或 2-肟基官能团而适用于分子内闭环的芳氧基乙酸反应相当差。这些系统的反应物消耗和产物形成的概况是通过原位核磁共振监测技术获得的。对一系列不同的催化剂形式进行了效率和易用性测试。所提出的机制,涉及在 TiO2 上的空穴捕获2表面由羧酸盐随后 CO 2损失得到中间体的 EPR 光谱证据的支持。氘标记表明二氧化钛可能从表面羟基提供质子并提供电子和空穴,因此既是催化剂又是反应伙伴。