Thiourea–I2 as Lewis base–Lewis acid cooperative catalysts are developed for the iodochlorination of alkenes with in situ-generated iodinemonochloride (I–Cl). The Lewis base–Lewis acid cooperative system is sufficient to generate I–Cl from I2 with a chlorinating reagent at low temperature. Based on the solid-state structure of the active species, thiourea–I2 cooperatively captures I–Cl. By taking
硫脲-I 2作为路易斯碱-路易斯酸协同催化剂被开发用于用原位生成的一氯化碘(I-Cl)进行烯烃的碘氯化。刘易斯碱-路易斯酸协同体系足以在低温下用氯化剂从I 2生成I-Cl 。基于活性物质的固态结构,硫脲I 2协同捕获I Cl。通过利用I–Cl生成和在低温下控制I–Cl的优势,硫脲– I 2协同系统抑制了由高反应性游离I–Cl引起的副反应。
Cobalt-Catalyzed Enantioselective Cross-Electrophile Couplings: Stereoselective Syntheses of 5–7-Membered Azacycles
作者:Zhaoming Ma、Wenqiang Xu、Yun-Dong Wu、Jianrong Steve Zhou
DOI:10.1021/jacs.3c02829
日期:2023.8.2
chiral pyrox ligands catalyzed enantioselective reductivecouplings of nonconjugated iododienes with aryl iodides or alkenyl bromides. The reaction enabled stereoselective syntheses of 5–7-membered azacycles carrying quaternary stereocenters. Mechanistically, cross-electrophile selectivity originated from selective coupling of alkylcobalt(I) complexes generated after cyclization with aryl iodides.
The Heck/Suzuki tandem reaction has emerged as an essential strategy for the synthesis of complex molecules. Herein, an efficient palladium-catalyzed Heck/Suzuki tandem reaction of (Z)-1-iodo-1,6-dienes with organoboronic acids is described, providing various tetrahydropyridines in good to excellent yields under mild reactionconditions. The key to the success of this approach is the avoidance of the
Heck/Suzuki 串联反应已成为合成复杂分子的基本策略。本文描述了 ( Z )-1-碘-1,6-二烯与有机硼酸的有效钯催化 Heck/Suzuki 串联反应,在温和的反应条件下以良好至优异的产率提供各种四氢吡啶。这种方法成功的关键是避免在转金属步骤之前发生分子内第二次 Heck 插入。此外,还研究了该反应的不对称形式,以优异的产率和良好的对映选择性提供手性四氢吡啶。