CC BY-NC-ND 4.0 · SynOpen 2021; 05(04): 278-284
DOI: 10.1055/s-0040-1719843
paper

Asymmetric Sequential Michael Addition and Cyclization Reactions of 2-(2-Nitrovinyl)phenols Catalyzed by Bifunctional Amino-Squaramides

Eva Veverková
,
Pavlína Molnosiová
,
This research has been supported by the Slovak Grant Agency VEGA (VEGA 1/0414/16) and Slovak Research and Development Agency under the Contract no. APVV-18-0242.


Abstract

In this work, we describe the Michael addition–cyclization reaction of 2-(2-nitrovinyl)phenol with two different reactive Michael donors, which lead to chiral benzopyran derivatives. Specifically, bifunctional amino-squaramides with one or two chiral units in the side chains were evaluated as catalysts in these transformations. Furthermore, the utility of selected green solvents as reaction media for these processes was also tested. The best result was achieved with methyl-cyclopentanone-2-carboxylate as the Michael donor in ethyl (–)-l-lactate with quinine-based amino-squaramide as catalyst (yield 72%, dr >99:1, ee 99%).

Supporting Information



Publication History

Received: 29 July 2021

Accepted after revision: 26 August 2021

Article published online:
05 October 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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