Amidoglycosylation via Metal-Catalyzed Internal Nitrogen Atom Delivery
作者:Elana Levites-Agababa、Elnaz Menhaji、Lisa N. Perlson、Christian M. Rojas
DOI:10.1021/ol025634k
日期:2002.3.1
[reaction: see text] Rhodium and copper acyl nitrenoids are likely intermediates in amidoglycosylation reactions of allal 3-carbamates. Iodine(III)-mediated nitrenoid formation, interaction of this species with the glycal enol ether pi-system, and highly beta-stereoselective glycosylation occur in a one-pot process that requires no additional Lewis acid activation.
Iron(II)-promoted amidoglycosylation and amidochlorination of an allal C3–azidoformate
作者:David G. Churchill、Christian M. Rojas
DOI:10.1016/s0040-4039(02)01658-1
日期:2002.9
Iron(II) halides promoted intramolecular alkene amidation in a C3-allal azidoformate. In the presence of alcohols, one-pot beta-glycosylation followed. Without added alcohol, amidochlorination occurred using FeCl2, providing an anomeric mixture of glycosyl chlorides which could be used in subsequent silver ion-mediated couplings. A 2-amido glycosyl chloride with a nitrogen-bound iron center is proposed as the glycosylating agent for the in situ amidoglycosylations with FeCl2. (C) 2002 Elsevier Science Ltd. All rights reserved.
Photo Amidoglycosylation of an Allal Azidoformate. Synthesis of <i>β</i>-2-Amido Allopyranosides
作者:Cindy Kan、Charli M. Long、Moushumi Paul、Christina M. Ring、Sarah E. Tully、Christian M. Rojas
DOI:10.1021/ol0069002
日期:2001.2.1
azidoformate provoked intramolecular nitrene insertion into the glycal C=C unit and allowed direct incorporation of alcohol nucleophiles as beta-disposed substituents at C-1. The 2-amido allopyranoside products were elaborated via N-acylation and selective oxazolidinone hydrolysis, providing N-Boc-protected 2-amino sugars and simplifying stereochemicalassignments. Synthesis of the potentially labile allal