3366-47-0Relevant articles and documents
Pd(II)/PhI(OAc)2 promoted direct cross coupling of glucals with aromatic acids
Begum, Zubeda,Shankar,Sirisha,Reddy, B.V. Subba
, p. 1 - 3 (2018)
A highly efficient oxidative C2-aroyloxylation of D-glucal with aromatic carboxylic acids has been achieved for the first time using 5 mol% Pd(OAc)2 and 1 equiv of PhI(OAc)2 to produce C2-aroyloxyglycals in good yields. The use of excess of PhI(OAc)2 (2 equiv) provides C2-acyloxyglycal exclusively.
Pivaloyl-protected glucosyl iodide as a glucosyl donor for the preparation of β-C-glucosides
Triantakonstanti, Virginia V.,Toskas, Alexandros,Iordanidis, Nicolaos S.,Andreou, Thanos,Koftis, Theoharis V.,Gallos, John K.
supporting information, (2020/07/13)
A method for the selective synthesis of β-C-glucosides using α-D-tetra-O-pivaloylglucosyl iodide as a glucosyl donor is reported. Its diastereoselectivity differs from that of the respective acetyl-protected glucosyl bromide, as it reported in the literature under similar reaction conditions. The concentration of the catalyst, the solvent and the type of additive used are crucial factors that determine the reaction selectivity. This method has been applied in a short synthesis of dapagliflozin. The stability of α-D-tetra-O-pivaloylglucosyl iodide in CDCl3 and THF at reflux was also studied. All side products in the coupling and decomposition reactions were isolated and characterized, and possible pathways for their formation are proposed.
O-Glycosidation reactions promoted by in situ generated silver N-heterocyclic carbenes in ionic liquids
Talisman, Ian Jamie,Kumar, Vineet,Razzaghy, Jacqueline,Malhotra, Sanjay V.
experimental part, p. 883 - 890 (2011/06/20)
We herein report O-glycosidation reactions promoted via silver N-heterocyclic carbene complexes formed in situ in ionic liquids. Seven different room temperature ionic liquids were screened for the glycosidation reaction of 4-nitrophenol with tetra-O-acetyl-α-d-galactopyranosyl bromide. Good to excellent yields were obtained using Ag-NHC complexes derived from imidazolium halide salts to promote the glycosidation reaction, whereas yields considered moderate to low were obtained without use of the silver carbene complex. Anion metathesis of the ionic liquids with inexpensive alkylammonium halides also resulted in silver N-heterocyclic carbene formation and subsequent O-glycosidation in the presence of silver carbonate. Effective utility of this methodology has been demonstrated with biologically relevant acceptors (including flavones and steroids) where O-β-glycoside products were obtained selectively in moderate to good yields. We have also demonstrated that the Ag-NHC complex is a superior promoter to traditionally used silver carbonate for the glycosidation of polyphenolic acceptors. The ionic liquids used in the study could be recycled three times without apparent loss in activity.
