TEMPO 催化的交叉二卤化反应是通过氧化还原调节双亲电 X +试剂的复杂系统而建立的。形式上,ICl的,氯化溴,我2和Br 2产生在-原位,这使高区域选择性或立体选择性获得的iodochlorination,bromochlorination和均-二卤化产物无数与功能性的宽光谱。该方法条件温和,操作简单,可广泛应用于有机合成,例如两种药物的发散合成。通过详细的机械调查进行了自由基钟反应、频哪醇扩环和哈米特实验,证实了卤离子的中介作用。此外,提出了一种基于 TEMPO 多功能催化作用的动态催化模型来解释选择性结果。
Homogeneous and Nanoparticle Gold-Catalyzed Hydrothiocyanation of Haloalkynes
作者:Xiaojun Zeng、Bocheng Chen、Zhichao Lu、Gerald B. Hammond、Bo Xu
DOI:10.1021/acs.orglett.9b00728
日期:2019.4.19
homogeneous and heterogeneous nanoparticle gold-catalyzed addition of sulfur nucleophiles to alkynes was developed. More specifically, gold-catalyzed hydrothiocyanation of haloalkynes gave good yields and good stereoselectivity of vinyl thiocyanates. Furthermore, a sulfur-based gold catalyst (PPh3AuSCN) has shown a unique reactivity in gold-catalyzed reactions such as the cyclization of N-propargylic amides
Nucleophilic Addition of Benzimidazoles to Alkynyl Bromides/Palladium-Catalyzed Intramolecular C–H Vinylation: Synthesis of Benzo[4,5]imidazo[2,1-<i>a</i>]isoquinolines
作者:Jinsong Peng、Guoning Shang、Chunxia Chen、Zhongshuo Miao、Bin Li
DOI:10.1021/jo302471z
日期:2013.2.1
An efficient "one-pot" route for the synthesis of benzo[4,5]imidazo[2,1-a] isoquinolines has been developed via nucleophilic addition of 2-aryl benzimidazoles to alkynyl bromides and subsequent palladium-catalyzed intramolecular C-H vinylation.
Oxidant- and Base-Free, Copper-Catalyzed Difluoromethylation of Haloalkynes