期刊
TETRAHEDRON LETTERS
卷 43, 期 39, 页码 6953-6955出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/S0040-4039(02)01590-3
关键词
-
Various Lewis acids have been examined as agents which react with N-iodosuccinimide to release iodonium ion for activating n-pentenylorthoester (NPOE) donors, particularly for coupling to acceptors that have acid-labile protecting groups. Although many of the reagents do not tolerate cyclic acetals, (BF3Et2O)-Et-. does. However, the latter cleaves p-methoxybenzyl (PMB), making it possible to use this Lewis acid to simultaneously promote coupling of NPOEs and remove PMB groups. Of several transition metal salts investigated, ytterbium triflate is outstanding in its ability to promote NPOE Coupling With complete preservation of acid-labile protecting groups. (C) 2002 Elsevier Science Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据