Asymmetric Aza-Diels–Alder Reactions of in Situ Generated β,β-Disubstituted α,β-Unsaturated N–H Ketimines Catalyzed by Chiral Phosphoric Acids
作者:Shunlong He、Huanchao Gu、Yu-Peng He、Xiaoyu Yang
DOI:10.1021/acs.orglett.0c01994
日期:2020.7.17
A novel asymmetricsynthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels–Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl- and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing
KI/TBHP-mediated oxidative cross coupling of enamines with carboxylic acids has been realized for the synthesis of functionalized 2H-azirines through the azirination of enamine intermediates. The metal-free strategy has several notable features, including the formation of C–O and C–N bonds in a one-pot procedure, broad functional group tolerance, good reaction yields, short reaction time, and high
KI / TBHP介导的烯胺与羧酸的氧化交叉偶联已通过烯胺中间体的叠氮化反应用于官能化2 H-叠氮基的合成。不含金属的策略具有几个显着特征,包括在一锅法中形成C-O和C-N键,官能团耐受性广,反应产率高,反应时间短和原子经济性高。这是通过KI / TBHP介导的烯胺和羧酸的分子间交叉偶联直接形成官能化的2 H-叠氮基的第一个例子。