A new procedure for thioester deprotection using thioglycolic acid in both homogeneous and heterogeneous phase

TETRAHEDRON

卷:94

Article

Villamil, Valentina^1,2  Saiz, Cecilia¹  Mahler, Graciela¹ 

[1] Univ Republica, Fac Quim, Lab Quim Farmaceut DQO, Gral Flores 2124, Montevideo 11800, Uruguay

[2] Univ Republ UdelaR, Fac Quim, Grad Program Chem, Montevideo 11800, Uruguay

关键词: Bisthiazolidine;    Oxazolidine;    Transthioesterification;    Thioester deprotection;    Recycling resin;    Polymer-supported thioglycolic acid;    Thioglycolic acid;    Polymer-supported reagent;   

DOI  :  10.1016/j.tet.2021.132335

来源: Elsevier

【 摘 要 】

Classic acetyl thioester protection/deprotection methodologies are widely used in organic synthesis, but deprotection step usually requires harsh conditions not suitable for labile substrates. In this work, a new method for thioester deprotection using a thiotransesterification approach is described. Firstly, thio-glycolic acid (TGA) was identified as a good deprotecting reagent in solution. In order to develop a thiol polymer-supported reagent, TGA was anchored to a PEG-based resin through an amide bond (TG-NCO-SH). Both homogeneous and heterogeneous approaches were conveniently carried out at room tem-perature, in aqueous buffer at pH 8. The mild conditions were suitable for alkyl and phenyl thioesters. Moreover labile thioesters containing thiazolidine and oxazolidine scaffolds, bearing amine, ester and acetal functionalities were also deprotected. The polymer-supported TGA gave better deprotection yields compared to TGA in solution, yields ranging from 61 to 90%. The feasibility of the recovery and reuse of TG-NCO-SH reagent was explored, showing it can be reused at least five times without lossing the activity. (c) 2021 Elsevier Ltd. All rights reserved.

【 授权许可】

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