1423754-13-5Relevant articles and documents
Organocatalytic asymmetric Michael addition of aliphatic aldehydes to indolylnitroalkenes: Access to contiguous stereogenic tryptamine precursors
Chen, Jian,Geng, Zhi-Cong,Li, Ning,Huang, Xiao-Fei,Pan, Feng-Feng,Wang, Xing-Wang
, p. 2362 - 2372 (2013/05/21)
Because of the importance of the indole framework and the versatile transformation of nitro and formyl groups, the efficient synthesis of optically pure 2-alkyl-3-(1H-indol-3-yl)-4-nitrobutanals, one type of tryptamine precursors are of great interest for pharmaceutical and biological research. Herein, the Michael addition of aliphatic aldehydes to indolylnitroalkenes has been developed using (S)-diphenylprolinol trimethylsilyl ether as an organocatalyst, which provides the desired optically pure syn 2-alkyl-3-(1H-indol-3-yl)-4-nitrobutanal derivatives in up to 98% yield with up to >99:1 dr and >99% ee. To show the synthetic usefulness of this methodology, optically active 2-alkyl-4-nitro-3-(1-tosyl-1H-indol-3-yl)butan-1- ol and tryptamine derivatives are readily obtained by stepwise systematic transformations.