2-Protecting groups for 5-lithiation in the syntheses of imidazoles

Autor:	Raphael I. Ngochindo
Rok vydání:	1990
Předmět:	chemistry.chemical_classification chemistry.chemical_compound chemistry Decarboxylation Reagent Substituent Organic chemistry Cleavage (embryo) Protecting group Sulfonamide
Zdroj:	Journal of the Chemical Society, Perkin Transactions 1. :1645
ISSN:	1364-5463 0300-922X
Popis:	Various substituents have been examined as possible 2-protecting groups against organolithium reagents in the syntheses of imidazoles on the basis of the ease of decarboxylation of imidazole-2-carboxylic acids and cleavage of the C(2)–Si bond. The tertiary amido function and t-butyldimethylsilyl (TBDMS) group at the 2-position permit quantitative 5-lithiation of N-substituted imidazoles. Deprotection of the amido function occurs under alkaline conditions while the TBDMS group is removed by several reagents. The TBDMS substituent is stable to butyl-lithium at temperatures up to –10 °C.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::941cff9efa120367f0c2b86cce01de83 https://doi.org/10.1039/p19900001645 Zobrazit plný text záznamu