0000000000121722
AUTHOR
Chakib Hajji
Chemoselective reactions of N1-methyl-2-hydroxy-3-methylamino-3-phenylpropanamide with electrophiles. Synthesis of chiral hexahydro-4-pyrimidinones and oxazolidines
Abstract The reactivity of (2S,3S)-N1-methyl-2-hydroxy-3-methylamino-3-phenylpropanamide 1 , containing three nucleophilic centres has been studied against dihaloalkanes and aldehydes. Hexahydro-4-pyrimidinones or oxazolidines were obtained chemoselectively. Experimental results were explained by ‘ab initio’ calculations.
Experimental and theoretical DFT study of the reaction of 3-amino-1,2-diols with dichloromethane and paraformaldehyde
Abstract The reactions of 3-phenyl-3-methylamino-1,2-propanediol 1a and 3-[(tert-butyldimethylsilyl)oxy]-1-methylamino-1-phenyl-2-propanol 1b with (CH2O)n and CH2Cl2 are appropriate procedures for the preparation of 1,3-oxazines or 1,3-oxazolidines under proper selection of kinetic or thermodynamic reaction conditions. The reaction of 1b with (CH2O)n or CH2Cl2, affords the oxazolidine 2b under kinetic conditions and then this compound can be slowly converted into 5-[(tert-butyldimethylsilyl)oxy]-3-methyl-4-phenyl-3,4,5,6-tetrahydro-2H-1,3-oxazine 3b under thermodynamic control. The mechanism proposed for this transformation and the effect of polar solvents on the acceleration of the reactio…
Reaction of 3-Methylamino-1,2-diols with Dihalomethanes. Synthesis of Chiral 4-Substituted 3-Methyltetrahydro-1,3-oxazin-5-ols
Abstract Enantiomerically pure 4,5-disubstituted 3-methyltetrahydro-1,3-oxazines have been obtained by reaction of 3-methylamino-1,2-diols with dichloromethane by regioselective differentiation of hydroxyl groups.
Asymmetric synthesis of (−)-pseudoephedrine from (2S,3S)-3-phenyloxiran-2-ylmethanol. Stereospecific interchange of amino and alcohol functions
Abstract A ring-opening reaction of N -methylaziridines with Boc 2 O/NaI has been applied to the asymmetric synthesis of pseudoephedrine. 3-Methylamino-3-phenyl-1,2-propanediol 1 , derived from (2 S ,3 S )-3-phenyloxiran-2-ylmethanol, was converted into the oxazolidin-2-one 4 , a precursor of pseudoephedrine. The reaction occurs with a stereospecific interchange of amino and alcohol functions.
Synthesis of 1,3-Oxazolidines and 1,3-Dioxolanes by Reaction of (2R, 3R)-3-Methylamino-3-phenyl-1,2-propanediol with Electrophiles
Abstract The chemoselective reaction of (2R, 3R)-3-methylamino-3-phenyl-1,2-propanediol 1 with dimethoxypropane and dichloromethane under different conditions are reported as useful preparative procedures, for the synthesis 1,3-oxazolidines and 1,3-dioxolanes.
Synthesis of 1,3-Oxazolidines and 1,3-Dioxolanes by Reaction of (2R,3R)-3-Methylamino-3-phenyl-1,2-propanediol with Electrophiles.
Abstract The chemoselective reaction of (2R, 3R)-3-methylamino-3-phenyl-1,2-propanediol 1 with dimethoxypropane and dichloromethane under different conditions are reported as useful preparative procedures, for the synthesis 1,3-oxazolidines and 1,3-dioxolanes.
Study of cyclic derivatives of 1,2-and 1,3-aminoalcohols as chiral catalysts in additions of diethylzinc to benzaldehyde
The enantioselectivity of the addition reactions of diethylzinc to benzaldehyde in the presence of cyclic derivatives of 1,2- and 1,3-aminoalcohols as catalysts has been studied.
Oxidation of aminodiols mediated by homogeneous and heterogeneous TEMPO
The conversion of amino diols to aminohy- droxy acids by oxidation of the primary hydroxy group mediated by homogeneous and heterogeneous TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl radi- cal) is reported. The synthesis uses NaOCl as primary oxidant and TEMPO, either dissolved in the homoge- neous phase or entrapped in a sol-gel matrix, as cata- lytic mediator. Homogeneous TEMPO is suitable for the oxidation of aliphatic methylamino diols, while the hybrid organic-inorganic silica sol-gel catalysts are more selective mediators for the oxidation of ben- zylic amino diols like the potent antibiotic chloram- phenicol which, under homogeneous conditions, are unselectively oxidized to benzoic ac…