Ytterbium(III) trifluoromethanesulfonate for specific activation of n-pentenyl orthoesters in the presence of acid-sensitive functionalities

被引：37

作者：

Jayaprakash, KN ^{[1
]}

Radhakrishnan, KV ^{[1
]}

Fraser-Reid, B ^{[1
]}

机构：

[1] Nat Prod & Glycotechnol Res Inst, Durham, NC 27706 USA

来源：

TETRAHEDRON LETTERS | 2002年 / 43卷 / 39期

关键词：

D O I：

10.1016/S0040-4039(02)01590-3

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

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.

引用

页码：6953 / 6955

页数：3