chemo- and α-regioselective asymmetric Michaeladdition of γ,γ-disubstituted α,β-unsaturatedaldehydes to nitroolefins has been presented in excellent diastereo- and enantioselectivities (dr up to >99:1, 93−96% ee) via dienamine catalysis. The Michael adducts have been efficiently converted to a number of optically pure cyclic frameworks with versatile scaffolddiversity.
Lewis Acid Catalyzed Intramolecular Direct Ene Reaction of Indoles
作者:Bo Han、You-Cai Xiao、Yuan Yao、Ying-Chun Chen
DOI:10.1002/anie.201005296
日期:2010.12.27
How to fuse heterocycles: The direct enamine–imine isomerization of indoles and subsequent intramolecular imino‐ene has been observed under Lewisacidcatalysis. This unique reaction occurred for indoles that contain a tethered olefin functionality, and led to fused indoline heterocycles with excellent diastereocontrol (see scheme).
Synthesis of Indolyl‐1,3‐dienes from
<i>β</i>
‐Sulphonyl Aldehydes through One‐Pot Sequential Brønsted Acid/Base Catalysis
作者:Ganesh Karan、Samrat Sahu、Modhu Sudan Maji
DOI:10.1002/ejoc.202200240
日期:2022.5.13
Syntheses of dienyl pyrroles and indoles were achieved by using β-sulfonyl aldehydes through transition-metal-free one-pot sequential Brønstedacid/base catalysis. This transformation enables the access to various aliphatic as well as aromatic substituted 1,3-dienes. Further, trienyl indole was also synthesized employing this strategy.