Lei Tao, Appleson Theresa, Breder Alexander
Institut für Organische Chemie, Universität Regensburg, Universitätstrasse 31, 93053 Regensburg, Germany.
ACS Catal. 2024 Jun 11;14(12):9586-9593. doi: 10.1021/acscatal.4c01327. eCollection 2024 Jun 21.
Herein, the intermolecular, photoaerobic aza-Wacker coupling of azoles with alkenes by means of dual and ternary selenium-π-acid multicatalysis is presented. The title method permits an expedited avenue toward a broad scope of -allylated azoles and representative azinones under mild conditions with broad functional group tolerance, as is showcased in more than 60 examples including late-stage drug derivatizations. From a regiochemical perspective, the protocol is complementary to cognate photoredox catalytic olefin aminations, as they typically proceed through either allylic hydrogen atom abstraction or single electron oxidation of the alkene substrate. These methods predominantly result in C-N bond formations at the allylic periphery of the alkene or the less substituted position of the former π-bond (i.e., -Markovnikov selectivity). The current process, however, operates through a radical-polar crossover mechanism, which solely affects the selenium catalyst, thus allowing the alkene to be converted strictly through an ionic two-electron transfer regime under Markovnikov control. In addition, it is shown that the corresponding -vinyl azoles can also be accessed by sequential or one-pot treatment of the allylic azoles with base, thus emphasizing the exquisite utility of this method.
在此，我们展示了通过二元和三元硒-π-酸多催化作用实现的唑类与烯烃的分子间光有氧氮杂瓦克耦合反应。该标题方法为在温和条件下制备多种烯丙基化唑类和代表性氮杂环丁二酮提供了一条快捷途径，具有广泛的官能团耐受性，超过60个实例（包括后期药物衍生化）展示了这一点。从区域化学角度来看，该方案与相关的光氧化还原催化烯烃胺化反应互补，因为后者通常通过烯丙基氢原子提取或烯烃底物的单电子氧化进行。这些方法主要导致在烯烃的烯丙基外围或前π键的取代较少位置形成C-N键（即反马氏选择性）。然而，当前的过程通过自由基-极性交叉机制运行，该机制仅影响硒催化剂，从而使烯烃在马氏控制下严格通过离子双电子转移机制进行转化。此外，研究表明，通过用碱对烯丙基唑进行顺序或一锅法处理，也可以得到相应的乙烯基唑，从而强调了该方法的出色实用性。
