The preparation of polymer bound β-ketoesters and their conversion into an array of oxazoles
作者:Bruce Clapham、Sang-Hyeup Lee、Guido Koch、Jürg Zimmermann、Kim D. Janda
DOI:10.1016/s0040-4039(02)01076-6
日期:2002.7
A series of diverse polymer bound beta-ketoesters have been prepared using a transesterification reaction between t-butyl beta-ketoesters and a hydroxybutyl functionalized JandaJel resin. Additionally, these highly useful polymer bound substrates have also been prepared using a transesterification reaction with commercially available methyl or ethyl beta-ketoesters using lithium perchlorate as a catalyst. The polymer bound beta-ketoesters were then converted into the corresponding alpha-diazo-beta-ketoesters using standard diazo transfer conditions and these products were utilized in the synthesis of an array of oxazoles. (C) 2002 Elsevier Science Ltd. All rights reserved.
Solid-phase synthesis of oxazolones and other heterocycles via Wang resin-bound diazocarbonyls
作者:Makoto Yamashita、Sang-Hyeup Lee、Guido Koch、Juerg Zimmermann、Bruce Clapham、Kim D. Janda
DOI:10.1016/j.tetlet.2005.06.061
日期:2005.8
The preparation of Wang resin bound alpha-diazo-beta-ketoesters is described. These highly useful intermediates were used for the synthesis of a series of heterocycle libraries, which were obtained from the resin using TFA cleavage. In addition, a novel route for the synthesis of oxazolones using an N-H insertion strategy is disclosed. (c) 2005 Elsevier Ltd. All rights reserved.