Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “IMINES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMed2006

Modeling cell membrane transport: interaction of guanidinylated poly(propylene imine) dendrimers with a liposomal membrane consisting of phosphate-based lipids.

Mixed anionic liposomes consisting of dihexadecyl phosphate, phosphatidylcholine, and cholesterol were employed as model systems for assessing the ability of a series of functionalized dendrimers, bearing a varying number of guanidinium groups at their surface, to translocate across the liposomal bilayers. At low guanidinium/phosphate molar ratios or when weakly guanidinylated dendrimeric derivatives were employed, the dendrimeric derivative acted as a kind of "molecular glue" leading to a simple adhesion of the liposomes. Liposomal fusion occurred to a certain extent at high guanidinium/phosphate molar ratios or when highly guanidinylated dendrimeric derivatives were employed. Furthermore, translocation of these dendrimeric derivatives to the liposomal core was observed for low to medium guanidinylation and at low guanidinium/phosphate molar ratios which was, however, enhanced when the lipid bilayer was in its fluid liquid-crystalline phase. Thus, an optimum balance is required between the binding strength of guanidinium with the phosphate groups and the degree of hydrophilicity of the guanidinylated dendrimers for the transport of the latter to the liposomal core to occur.

Biological Transport↗
PubMed2002

Fluoroalkyl alpha,beta-unsaturated imines. Valuable synthetic intermediates from primary fluorinated enamine phosphonates.

[reaction: see text] A simple method for the preparation of fluoroalkyl allylamines or alpha,beta-unsaturated ketones by an olefination reaction of primary enamine phosphonates and aldehydes, followed by selective reduction with hydrides or hydrolysis, is reported. Fluorinated beta-amino nitriles are also obtained by an olefination reaction of primary enamine phosphonates with aldehydes and subsequent addition of metalated acetonitrile.

Journal Article↗
PubMed2004

Oxazolidine ring opening and isomerization to (E)-imines. Asymmetric synthesis of aryl-alpha-fluoroalkyl amino alcohols.

[reaction: see text] A base-induced ring opening/imine isomerization/diastereoselective organometallic addition sequence on 4-substituted 2-perfluoroalkyl-1,3-oxazolidines has been developed for the asymmetric synthesis of aryl alpha-perfluoroalkylamine derivatives. This practical method provides chiral amino alcohols in 60-95% yield with uniformely high diastereoselectivities ranging from 35:1 to >100:1.

Journal Article↗
PubMed2004

Asymmetric synthesis of alpha-amino 1,3-dithioketals from sulfinimines (N-sulfinyl imines). Synthesis of (2S,3R)-(-)-3-hydroxy-3-methylproline.

[reaction: see text] N-Sulfinyl alpha-amino 1,3-dithioketals are prepared in high de and good yield by treating sulfinimines with lithio-1,3-dithianes. Selective removal of the N-sulfinyl or the thioketal groups affords stable alpha-amino 1,3-dithioketals and N-sulfinyl alpha-amino ketones, respectively. This new sulfinimine-derived chiral building block is employed in the asymmetric synthesis of polyoxypeptin amino acid (2S,3R)-(-)-3-hydroxy-3-methylproline.

Catalysis↗
PubMed2006

Tin-free intermolecular addition of primary alkyls to imines via the dimethylzinc-air radical process.

[reaction: see text] A dimethylzinc-air initiator was applied to the generation of primary alkyl radicals from alkyl iodides. The addition of the generated primary alkyl radicals to N-tosylimines was accelerated by the action of boron trifluoride-diethyl etherate and copper(II) triflate to give the corresponding adducts in good yields after 2-3 h. Air oxygen was essential for the reaction to proceed, showing involvement of a radical process in the reaction.

Journal Article↗
PubMed2006

Catalytic asymmetric synthesis of alpha,alpha,alpha-trifluoromethylamines by the copper-catalyzed nucleophilic addition of diorganozinc reagents to imines.

[reaction: see text] A copper-catalyzed asymmetric addition of diorganozinc reagents to N-phosphinoylimines has been developed for the synthesis of chiral alpha,alpha,alpha-trifluoromethylamines. The trifluoromethyl ketimines, generated in situ from the corresponding hemiaminals, led to the chiral amides in high yields (71-89%) and excellent enantiocontrol (91-99% ee).

Journal Article↗
PubMed2006

Copper(I)-Fesulphos Lewis Acid catalysts for enantioselective Mannich-type reaction of N-sulfonyl imines.

[reaction: see text] Copper(I) complexes of Fesulphos ligands are efficient chiral Lewis acid catalysts in the Mannich-type addition of silyl enol ethers of ketones, esters, and thioesters to N-(2-thienyl)sulfonyl aldimines. The corresponding optically active beta-amino carbonyl derivatives were obtained in good yields (58-91%) and with moderate to good enantioselectivity (61-93% ee). Removal of the N-activating group was achieved under mild conditions by simple treatment of the products with Mg in methanol.

Journal Article↗