imidazole-containing organoboronic acid catalysts is described. This catalytic process with low catalyst loading enables the introduction of a wide variety of acyl functional groups into the equatorial position of cis-vicinal diols in unprotected hexapyranosides with excellent site selectivity. This is the first example that uses a Lewis base-containing boronicacid to enhance the nucleophilicity of
Site-Selective Acylations with Tailor-Made Catalysts
作者:Florian Huber、Stefan F. Kirsch
DOI:10.1002/chem.201600790
日期:2016.4.18
The acylation of alcohols catalyzed by N,N‐dimethylaminopyridine (DMAP) is, despite its widespread use, sometimes confronted with substrate‐specific problems: For example, target compounds with multiple hydroxy groups may show insufficient selectivity for one hydroxyl, and the resulting product mixtures are hardly separable. Here we describe a concept that aims at tailor‐made catalysts for the site‐specific
Regioselective benzoylation of glycopyranosides by benzoic anhydride in the presence of Cu(CF3COO)2
作者:Evgeny V. Evtushenko
DOI:10.1016/j.carres.2012.06.020
日期:2012.10
Benzoylation of methyl and benzyl glycopyranosides by benzoic anhydride in acetonitrile in the presence of copper(II) trifluoroacetate as a promoter has given monobenzoates with a good yield and high regioselectivity. The composition of monobenzoates depended both on a configuration of hydroxyl groups and on a configuration of aglycone. The simple syntheses of the monobenzoates of some glycosides are
Regioselective Benzoylation of Glycopyranosides by Benzoyl Chloride in the Presence of MoO<sub>2</sub>(acac)<sub>2</sub>
作者:E. V. Evtushenko
DOI:10.1080/07328303.2010.549258
日期:2010.11.1
Benzoylation of methyl and benzyl glycopyranosides by benzoyl chloride in the presence of MoO2(acac)(2) as a catalyst resulted in 3-benzoates with good yield and high regioselectivity. Simple synthesis of the monobenzoates of some glycopyranosides is suggested.