O-Glycosidation reactions promoted by in situ generated silver N-heterocyclic carbenes in ionic liquids.

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-ß-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.

Carbohydrate-based drugs in the treatment of epilepsy, depression and other affective disorders.

Mental illness affects a quarter of the US population. Recently, it has been shown that new, carbohydrate-based drugs hold promise in the treatment of central nervous system (CNS) disorders. A variety of ways in which drugs of this sort may reduce the symptoms of epilepsy, depression and other affective disorders have been proposed, including: targeting the immune system, disrupting glycolysis, acting at different sites in the hypothalamic-pituitary-adrenal (HPA) axis, and targeting specific biochemical pathways such as the inositol pathway. In the present review, the structure-activity relationships (SARs) of a wide variety of CNS-active carbohydrates are presented.

Amino substituted analogs of 1-phenyl-3-phenylimino-2-indolones with potent galanin Gal3 receptor binding affinity and improved solubility.

A series of amino analogs of 1,3-dihydro-1-phenyl-3-[[3-(trifluoromethyl)phenyl]imino]-2H-indol-2-one (1) were synthesized to improve aqueous solubility, while retaining high affinity for the human galanin Gal3 receptor. A very potent analog (9e, 1,3-dihydro-1-[3-(2-pyrrolidinylethoxy)phenyl]-3-[[3-(trifluoromethyl)phenyl]imino]-2H-indol-2-one, Ki=5 nM) shows good selectivity and solubility of 48 microg/mL at pH 7.4.