Efficient Two-Step Multifunctionalization of Substituted 2-Hydroxyglycopyranosides
摘要:
A straightforward route to diversely functionalized glycopyranosides is reported. 2,3-Enopyranosides, 2- and/or 3-azido-, 2-halopyranosides, and a hex-3-ulose, among other - and -glycopyranosides are easily obtained in good to excellent yields from 2-hydroxyglycopyranosides by means of a two-step process involving trifluoromethanesulfonation and subsequent treatment with the appropriate nucleophilic agent.
4,6-O-Benzylidene protected D-glucal, a useful synthetic intermediate, may be accessed from the extremely cheap and readily available starting material alpha-methyl glucopyranoside, via a simple four-step reaction sequence involving selective triflation and iodide displacement at C-2. (C) 2003 Elsevier Science Ltd. All rights reserved.
Carbohydrate-based N-heterocyclic carbenes for enantioselective catalysis
作者:Alexander S. Henderson、John F. Bower、M. Carmen Galan
DOI:10.1039/c4ob02056a
日期:——
Versatile syntheses of C2-linked and C2-symmetric carbohydrate-based imidazol(in)ium salts from functionalised amino-carbohydrate derivatives are reported. The novel NHCs were ligated to [Rh(COD)Cl]2 and evaluated in Rh-catalysed asymmetrichydrosilylation of ketones with good yields and promising enantioselectivities.
A straightforward route to diversely functionalized glycopyranosides is reported. 2,3-Enopyranosides, 2- and/or 3-azido-, 2-halopyranosides, and a hex-3-ulose, among other - and -glycopyranosides are easily obtained in good to excellent yields from 2-hydroxyglycopyranosides by means of a two-step process involving trifluoromethanesulfonation and subsequent treatment with the appropriate nucleophilic agent.
A facile synthesis of 4,6-O-benzylidene glucal
作者:David J. Chambers、Graham R. Evans、Antony J. Fairbanks
DOI:10.1016/s0957-4166(03)00288-x
日期:2003.7
4,6-O-Benzylidene protected D-glucal, a useful synthetic intermediate, may be accessed from the extremely cheap and readily available starting material alpha-methyl glucopyranoside, via a simple four-step reaction sequence involving selective triflation and iodide displacement at C-2. (C) 2003 Elsevier Science Ltd. All rights reserved.