An efficient and high-yielding one-pot synthesis of 4-acyl-1,2,3-triazoles via triisopropylsilyl-protected ynones
摘要:
A practical and efficient process has been developed for the synthesis of 1-substituted 4-acyl-1H-1,2,3-triazoles using a three-step one-pot synthetic approach. This transformation involves an initial preparation of triisopropylsilyl (TIPS)-protected ynones from acid chlorides and TIPS-acetylene, followed by a AgF-mediated TIPS deprotection and Cu-catalyzed Huisgen cycloaddition. The increased chemical stability of TIPS-protected ynones was an important factor in the high overall product yield. (C) 2011 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Huisgen 1,3-Dipolar Cycloaddition under Oxidative Conditions: Polymer-Assisted Assembly of 4-Acyl-1-Substituted-1,2,3-Triazoles
作者:Paula M. Diz、Alberto Coelho、Abdelaziz El Maatougui、Jhonny Azuaje、Olga Caamaño、Álvaro Gil、Eddy Sotelo
DOI:10.1021/jo400800j
日期:2013.7.5
We herein document the first example of a reliable copper-catalyzed Huisgen 1,3-dipolar cycloaddition underoxidativeconditions. The combined use of two polymer-supported reagents (polystyrene-1,5,7-triazabicyclo[4,4,0]dec-5-ene/Cu and polystyrene-2-iodoxybenzamide) overcomes the thermodynamic instability of copper(I) species toward oxidation, enabling the reliable Cu-catalyzed Huisgen 1,3-dipolar
A copper-catalyzed three-component reaction of methyl ketones, organic azides, and various one-carbon (C1) donors was developed that provides 4-acyl-1,2,3-triazoles in moderate to good yields. While DMF, DMA, TMEDA, or DMSO can serve as the C1 donor, best yields were obtained using DMF. The transformation is proposed to proceed via an oxidative C–H/C–H cross-dehydrogenative coupling followed by an
from readily-available aryl–alkyl ketones (or alcohols) and different organic azides. Moreover, the reaction used environmentallyfriendlydimethylcarbonate (DMC) as the solvent and air as the oxidant, and H2O was the only by-product, so it provides a green and practical synthetic method for 1,2,3-triazoles.