The Effectivity of 1H-Triazoles and -Tetrazoles as Activators in Acid-Catalyzed Phosphoramidite Alcoholysis

✍ Scribed by Erkki. J. Nurminen; Jorma K. Mattinen; Harri Lönnberg

• Book ID: 102254255
• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: German
• Weight: 75 KB
• Volume: 86
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200390157

✦ Synopsis

Abstract

The efficiency of 5‐nitro‐1,2,4‐1__H__‐triazole (3), 5‐(methylthio)‐1__H__‐tetrazole (4), and 5‐(4‐nitrophenyl)‐1__H__‐tetrazole (5) as activators in phosphoramidite alcoholysis has been studied relative to 1__H__‐tetrazole (6). Reactions of these azoles with diisopropyl (diisopropylamido)phosphite (1a) were followed in THF, and the rates were found to increase with increasing acidity of the azoles. The Brønsted α value of 0.7 determined for this dependence is in agreement with data published earlier.