研究室工作进展 Jun. 4th, 2013.
Oxidation of C-H bonds to C=O bonds by O2 only or N-oxides and DMSO: Synthesis of Δ1-bipyrrolinones and pyrrolino[3,2-b]pyrrolinones from 2,6-diazasemibullvalenes
Shaoguang Zhang, Ming Zhan, Qian Luo, Wen-Xiong Zhang and Zhenfeng Xi*
Chem. Commun. 2013, DOI: 10.1039/C3CC43061H
2,6-Diazasemibullvalenes (NSBVs) readily reacted with oxygen under mild conditions, affording Δ1-bipyrrolinones via C-N bond cleavage and C-H bond oxidation. Pyrrolino[3,2-b]pyrrolinone derivatives were efficiently generated when NSBVs were treated with N-oxides in the presence of Lewis acids. Δ1-Bipyrrolinones thus obtained could be readily transformed into other heterocycles.
Oxidation of C-H bonds to C=O bonds by oxygen (O2) is a very important and useful process. In general, additives or promoters such as bases, transition metal complexes, and photosensitizers are required to realize such a process. On the contrary, there are very few reports on oxidation of a C-H bond to a C=O bond by oxygen only, without any additives or promoters. 2,6-Diazasemibullvalene (NSBV) is composed of structurally and chemically interesting polycyclic strained skeletons. It is featured with a strained aziridine core as well as rapid aza-Cope rearrangement.
This study added more knowledge to the understanding of the reaction chemistry of diazasemibullvalenes, a class of unique compounds.
亮点介绍
结构决定性质。
C-H键被氧气氧化成C=O键是一个重要反应。但是，一般C-H键在没有任何添加物的存在下是很难被氧气直接氧化成C=O键的。氮杂半瞬烯的2个C-H键在室温下被氧气直接高效氧化成2个相应的C=O键是由氮杂半瞬烯的结构所决定的。本工作再次表明氮杂半瞬烯结构的独特性和有用性。