Isocyanide based multicomponent reactions of oxazolidines and related systems.
6496 - 6507.
N-Alkyloxazolidines react in a multicomponent reaction with carboxylic acids and isocyanides to give N-acyloxyethylamino acid amides. The previously reported reaction conditions were improved using a design of experiments approach (DoE). Under the optimised conditions, good yields of the N-acyloxyethylamino acid amide products are obtained both via a three- or four-component approach from N-alkylethanolamines, aldehydes/ketones, isocyanides and carboxylic acids. The reaction of oxazolidines without a nitrogen substituent was found to give either the expected Ugi products or the N-acyloxyethylamino acid amides depending on the choice of reaction conditions. Optimised reaction conditions were also developed for the ring-expansion of oxazolidines to morpholin-2-ones via reaction with an isocyanide followed by hydrolysis. The mechanistic pathway of the multicomponent reaction was briefly investigated using an O-18 labelling experiment. The carboxylic acid component can be replaced by a range of other acidic nucleophiles including thiobenzoic acid, thiophenol or 5-phenyltetrazole, which are incorporated via an alternative pathway. These latter reactions can also be applied to 2-aminotetrahydrofurans, 2-aminotetrahydropyrans or 4-hydroxybut-2-one, further extending the structural diversity of the multicomponent reaction products. (C) 2010 Elsevier Ltd. All rights reserved.
|Title:||Isocyanide based multicomponent reactions of oxazolidines and related systems|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||“NOTICE: this is the author’s version of a work that was accepted for publication in <Journal title>. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Tetrahedron,VOL 66, ISSUE 33, 14/08/2014 DOI http://dx.doi.org/10.1016/j.tet.2010.05.083|
|Keywords:||Multicomponent reactions, Isocyanides, Design of experiments, Oxazolidines, Ring-opening reactions, UGI-smiles Couplings, C-O Bond, Glycolaldehyde Dimer, 4-Component Reaction, Reductive Cleavage, Carboxylic-Acids, Primary Amines, Acetals, Thiols, Strategies|
|UCL classification:||UCL > School of BEAMS
UCL > School of BEAMS > Faculty of Maths and Physical Sciences
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