在有氧条件下从空气中引入氧原子在有机合成中起着重要作用。在此,布朗斯台德酸被发现是一种二合一的战略催化剂,在可见光条件下无需外部光催化剂即可将烯胺从β-氧代酰胺和胺转化为吡咯啉-4-酮。布朗斯台德酸可以抑制烯胺和1 O 2生成的[2 + 2]加合物的 C-C 键断裂,但最重要的是,它可以通过酸变色作用与烯胺和吡咯啉-4-酮产物形成光敏剂,促进1 O 2代。
In Situ Generated TEMPO Oxoammonium Salt Mediated Tandem Cyclization of β-Oxoamides with Amine Hydrochlorides for the Synthesis of Pyrrolin-4-ones
作者:Xuna Zhao、Tong-Xin Liu、Nana Ma、Guisheng Zhang
DOI:10.1021/acs.joc.7b00686
日期:2017.6.16
A novel in situ generated TEMPO oxoammonium salt mediated one-pot tandem reaction has been developed for the straightforward construction of pyrrolin-4-ones from readily available β-oxoamides with amine hydrochlorides. The reaction tolerates various functional groups and represents a reliable method for the synthesis of highly substituted pyrrolin-4-ones in good yields under mild conditions. Detailed
A novel Cu(II)-catalyzed cyclization of alpha-diazo-beta-oxoamides with amines has been developed, constituting a straightforward method to construct pyrrol-3(2H)-one rings. The intramolecular hydrogen bonding effect in alpha-diazo-beta-oxoamides plays an essential role in this reaction. A plausible reaction mechanism involving divergent generation and subsequent [2 + 3] cyclization of ketene and alpha-diazoimine