NHC‐Catalyzed Chemoselective Reactions of Enals and Aminobenzaldehydes for Access to Chiral Dihydroquinolines
作者:Shuquan Wu、Changyi Liu、Guoyong Luo、Zhichao Jin、Pengcheng Zheng、Yonggui Robin Chi
DOI:10.1002/anie.201909479
日期:2019.12.16
(NHC)-catalyzed reaction between α-bromoenals and 2-aminoaldehydes has been developed. Key steps include chemoselective reaction of the NHC catalyst with one of the aldehyde substrates (the bromoenal) to eventually generate an α,β-unsaturated acylazolium intermediate. Addition of the nitrogen atom of aminoaldehyde to the unsaturated azolium ester intermediate followed by intramolecular aldol reaction, β-lactone
Enantioselective Synthesis of Azaflavanones Using Organocatalytic 6-<i>endo</i>Aza-Michael Addition
作者:Shuanghua Cheng、Lili Zhao、Shouyun Yu
DOI:10.1002/adsc.201300920
日期:2014.3.24
A method to prepare highly enantioenriched azaflavanonesusing an organocatalytic 6‐endo aza‐Michael addition has been described. A variety of 2‐aryl‐, 2‐vinyl‐ and 2‐methylazaflavanones were prepared in good yields (53–84%) and excellent enantioselectivities (97.6:2.4 to 99.3:0.7 er).