Minisci 烷基化可用于通过烷基自由基加成对芳烃进行官能化。当前制备烷基自由基的方法遵循来自各种官能团的氧化或还原途径。开发超越这些传统方法的新战略仍然难以捉摸,但意义重大。在本文中,我们提出了一种氧化还原中性和无催化剂的方案,以在芳烃的三氟甲基化和一般烷基化的背景下产生烷基自由基。该协议通过 Norrish I 型概念产生烷基自由基,适应各种官能团并以良好的产率提供产品。该方法在光的辅助下鉴定了一系列化合物作为三氟甲基化和烷基化试剂。预计这些化合物可以在其他涉及自由基的反应中找到潜在的应用。
Catalytic and direct methyl sulfonylation of alkenes and alkynes using a methyl sulfonyl radical generated from a DMSO, dioxygen and copper system
作者:Yaojia Jiang、Teck-Peng Loh
DOI:10.1039/c4sc01901f
日期:——
This paper describes an efficient method to β-keto methyl sulfones and (E)-vinyl methyl sulfones using DMSO as the substrate. The methyl sulfonyl radical generated from DMSO in the presence of catalytic Cu(I) under O2 atmosphere is believed to be involved in this reaction. Isotopic labeling and 18O2 experiments were performed to investigate the reaction mechanism.
本文介绍了一种有效的方法,以DMSO为底物,制备β-酮甲基砜和(E)-乙烯基甲基砜。据信在O 2气氛下在催化性Cu(I)存在下由DMSO产生的甲基磺酰基自由基参与了该反应。进行同位素标记和18 O 2实验以研究反应机理。
strategy has been established for the synthesis of β‐oxo sulfonesvia visible light‐induced oxysulfonylation of alkenes with arylazo sulfones with dioxygen in air. The present photoinduced transformation proceeds smoothly at room temperature in the absence of an external photosensitizer, which not only provides a mild and efficient approach to various β‐oxo sulfones, but also opens a different reaction
Activemethylenecompounds are selectively monoalkylated with alkyl halides in benzene using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a base. Selectivity of monoalkylation decreases when the reaction is carried out in a polar solvent. Ethyl acetoacetate is O-acylated with acyl halides in the presence of DBU in acetonitrile to give the (E)-enol esters stereoselectively.