由过渡金属盐和氨氧基催化的有氧醇氧化是协同催化的突出例子。之前已经研究过 Cu/氨氧基催化剂,具有“综合协同性”的特点,其中 Cu II和氨氧基共同参与介导醇氧化。在这里,我们研究了一种互补的 Fe/氨氧基催化剂体系,并提供了“串联协同性”的证据,涉及氧化还原级联反应,其中醇被原位生成的氧代铵物质氧化,通过循环步进计时电流法在催化反应混合物中直接检测到. Cu 基和 Fe 基催化剂之间的机理差异源于使用硝酸铁 (III),它引发了 NO x基于氧化还原循环的氨氧基/羟胺氧化成氧代铵。Cu基和Fe基催化剂体系的不同机理表现在不同的醇氧化化学选择性和官能团相容性上。
Metal-Free Synthesis of Pyrrolo[1,2-a]quinoxalines Mediated by TEMPO Oxoammonium Salts
作者:Xiang-Ying Tang、Yue-fa Gong、Heng-rui Huo
DOI:10.1055/s-0037-1610131
日期:2018.7
cyclization–dehydrogenation process using one equivalent of the oxoammonium salt. We herein describe a novel TEMPO oxoammonium salt initiated Pictet–Spenglerreaction of imines, generated in situ from carbonyl compounds and pyrrole- or indole-containing substrates, to afford 4,5-dihydropyrrolo[1,2-a]quinoxalines or 5,6-dihydroindolo[1,2-a]quinoxalines in good to excellent yields. Moreover, a one-pot
摘要 我们在本文中描述了一种新型的TEMPO氧铵盐引发的亚胺的Pictet-Spengler反应,该反应是从羰基化合物和含吡咯或吲哚的底物就地产生的,以提供4,5-二氢吡咯并[1,2- a ]喹喔啉或5,6 -二氢吲哚并[1,2- a ]喹喔啉的收率为好至极好。此外,通过使用一当量的氧铵盐的环化-脱氢过程,一锅合成重要的生物学重要的喹喔啉。 我们在本文中描述了一种新型的TEMPO氧铵盐引发的亚胺的Pictet-Spengler反应,该反应是从羰基化合物和含吡咯或吲哚的底物就地产生的,以提供4,5-二氢吡咯并[1,2- a ]喹喔啉或5,6 -二氢吲哚并[1,2- a ]喹喔啉的收率为好至极好。此外,通过使用一当量的氧铵盐的环化-脱氢过程,一锅合成重要的生物学重要的喹喔啉。
作者:Federica Carlet、Greta Bertarini、Gianluigi Broggini、Alexandre Pradal、Giovanni Poli
DOI:10.1002/ejoc.202100026
日期:2021.4.22
An oxoammonium‐mediated α‐C(sp3) allylation of allyl‐ and benzyl ethers using allylsilanes as nucleophilic partners is disclosed. This new C−C bond forming C−H activation process allows to obtain the corresponding coupled products in moderate to good yields.
Synthesis of α-enaminones from cyclic ketones and anilines using oxoammonium salt as an oxygen transfer reagent
作者:Biping Xu、Yaping Shang、Xiaoming Jie、Xiaofeng Zhang、Jian Kan、Subhash Laxman Yedage、Weiping Su
DOI:10.1039/c9gc03845k
日期:——
A convenient and straightforward transformation of cyclicketones with anilines at room temperature has been developed using oxoammonium salt TEMPO+PF6− as an oxidant. This method enabled the synthesis of a broad range of α-enaminones. The 18O-labeling experiment demonstrated that oxoammonium salt served as the oxygen transfer reagent.
methods for oxidative rearrangement of tertiary allylic alcohols to β-substituted α,β-unsaturated carbonyl compounds employing oxoammonium salts are described. The methods developed are applicable to acyclic substrates as well as medium membered ring substrates and macrocyclic substrates. The counteranion of the oxoammonium salt plays crucial roles on this oxidative rearrangement.
is evaluated, intermediates along the reaction sequence have been trapped, and side-reactions identified. In addition, the X-ray structures of a complete set of these salts are reported and their reactivities studied. Specifically, chemoselective Suzuki coupling is observed at the dibenzothiophenium in the presence of iodides.
报道了一种从廉价的二苯并噻吩 S-氧化物和简单的芳烃开始制备 5-(芳基)二苯并噻吩鎓盐的合成方案。评估了有关芳烃性质的方法范围,捕获了反应序列中的中间体,并识别了副反应。此外,还报道了这些盐的整套 X 射线结构并研究了它们的反应性。具体而言,在碘化物存在下,在二苯并噻吩鎓处观察到化学选择性铃木偶联。