ABSTRACT
A general protocol for the enantioselective synthesis of 3-heterosubstituted-2-amino-1-ols was developed based on metal- free intramolecular regio- and stereoselective diene aziridination and regioselective opening. Kinetic resolution of the resulting (1'-NR1 R2 and 1'-SR)-4-oxazolidinones was performed using ABCs organocatalysts, expanding the application of this methodology.
ABSTRACT
Regio- and stereoselective oxyamination of dienes through a tandem rhodium-catalysed aziridination-nucleophilic opening affords racemic oxazolidinone derivatives, which undergo a kinetic resolution acylation process with amidine-based catalysts (ABCs) to achieve s values of up to 117. This protocol was applied to the enantioselective synthesis of sphingosine.
Subject(s)
Amidines/chemistry , Rhodium/chemistry , Acylation , Catalysis , Kinetics , Molecular Structure , StereoisomerismABSTRACT
The enantioselective addition of anilines to azoalkenes was accomplished through the use of a chiral phosphoric acid catalyst. The resulting α-arylamino hydrazones were obtained in good yields and excellent enantioselectivities and provide access to enantioenriched α-arylamino ketones. A serendipitous kinetic resolution of racemic α-arylamino hydrazones is also described.
Subject(s)
Hydrocarbons, Aromatic/chemical synthesis , Ketones/chemical synthesis , Alkenes/chemical synthesis , Alkenes/chemistry , Amination , Aniline Compounds/chemical synthesis , Aniline Compounds/chemistry , Hydrazones/chemical synthesis , Hydrazones/chemistry , Hydrocarbons, Aromatic/chemistry , Ketones/chemistry , StereoisomerismABSTRACT
The reaction of dienyl carbamates with PhI(OR)2 in the presence of rhodium catalysts affords vinyl aziridines which are in situ regio- and stereoselectively opened to afford oxyamination products resulting from a selective S(N)2 (Rh2(OAc)4/PhI(OPiv)2) or S(N)2' (Rh2(OPiv)4/PhI(OAc)2) opening. The scope and limitations of this tandem process are described.
