On the Necessity of One-Pot Tautomer Trapping in Asymmetric Michael Reactions of Arylideneisoxazol-5-ones
作者:Antonio Macchia、Valentina Dafnae Cuomo、Antonia Di Mola、Giovanni Pierri、Consiglia Tedesco、Laura Palombi、Antonio Massa
DOI:10.1002/ejoc.202000286
日期:2020.4.23
The issue of the obtaining of complex tautomeric mixtures of 4‐mono‐substituted isoxazol‐5‐ones has been overcome by the use of entrapping reactants in a one‐pot protocols of Michael reactions with arylideneisoxazol‐5‐ones. Asymmetric three components Michael/electrophilic tautomer‐entrapping and four‐component Knoevenagel/Michael/electrophilic‐tautomer‐entrapping methodologies have been developed
A bifunctional squaramide-catalysed enantioselective vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α,α-dicyanoalkenes
作者:Yu Wang、Cheng Niu、Dong-Hua Xie、Da-Ming Du
DOI:10.1039/d1ob01256h
日期:——
stereoselective synthesis of spiro isoxazolone-cyclohexenimines was developed using a bifunctional squaramide-catalysed vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α,α-dicyanoalkenes. The atom-economical cascade process can proceed smoothly under extremely low catalyst loading (1 mol%) and mild conditions, and the corresponding products were obtained
Highly Diastereo- and Enantioselective Synthesis of Isoxazolone-Spirooxindoles via Squaramide-Catalyzed Cascade Michael/Michael Addition Reactions
作者:Yu Wang、Da-Ming Du
DOI:10.1021/acs.joc.0c02150
日期:2020.12.4
been accomplished by squaramide-catalyzedcascadeMichael/Michael addition reactions under mild conditions. The corresponding isoxazolone-spirooxindoles with four continuous stereocenters were obtained in moderate to high yields with excellent stereoselectivities (up to >20:1 dr, 97% ee). The synthetic practicality of this methodology was illustrated by performing the reaction on a gram scale with
Falling-Solid Flash Vacuum Pyrolysis: An Efficient Preparation of Arylacetylenes
作者:Curt Wentrup、Jürgen Becker、Hans-Wilhelm Winter
DOI:10.1002/anie.201412431
日期:2015.5.4
Automated falling‐solid flash vacuumpyrolysis allows the rapid and efficient synthesis of a variety of arylacetylenes from 4‐arylmethylidene‐5(4H)‐isoxazolone derivatives, which were prepared from aldehyde precursors. The acetylenes are readily obtained in multigram quantities.