DBU-catalyzed tandem additions of electron-deficient 1,3-conjugated enynes with 2-aminomalonates: a facile access to highly substituted 2-pyrrolines
作者:Xiuzhao Yu、Guanghua Zhou、Junliang Zhang
DOI:10.1039/c2cc30840a
日期:——
An efficient, metal free approach to highly substituted 2-pyrrolines by DBU-catalyzed tandem additions (a formal [3+2] cycloaddition) of electron-deficient 1,3-conjugated enynes and 2-aminomalonates under mild conditions was developed.
Organocatalytic Formation of Chiral Trisubstituted Allenes and Chiral Furan Derivatives
作者:Pernille H. Poulsen、Yang Li、Vibeke H. Lauridsen、Danny K. B. Jørgensen、Teresa A. Palazzo、Marta Meazza、Karl Anker Jørgensen
DOI:10.1002/anie.201806238
日期:2018.8.13
by amino catalytic activation of either aldehydes or α,β‐unsaturated aldehydes for reaction with alkynyl‐substituted enones is presented. The reaction forms a variety of trisubstituted allenes in high yields and with excellent stereoselectivities. The utility of the reaction concept is demonstrated by the synthesis of chiral furan derivatives in high yields and stereoselectivities.
Organocatalytic hetero [4+2] cycloaddition reactions of 2-(1-alkynyl)-2-alkene-1-ones: metal-free access to highly substituted 4H-pyrans
作者:Xiuzhao Yu、Zhongyan Cao、Junliang Zhang
DOI:10.1039/c0ob00334d
日期:——
Highly substituted 4H-pyrans can be smoothly synthesized from readily available 2-(1-alkynyl)-2-alkene-1-ones by DBU- or n-Bu3P catalyzed hetero-[4+2] cycloaddition reactions, in which 2-(1-alkynyl)-2-alkene-1-ones act as both heterodiene and heterodinenophile.