1-(Alpha-aminobenzyl)-2-naphthol: a new chiral auxiliary for the synthesis of enantiopure alpha-aminophosphonic acids.
A new diastereoselective synthesis of alpha-aminophosphonates has been developed, based on the reaction, in the presence of trifluoroacetic acid, of trialkyl phosphites with chiral imines derived from (R)- or (S)-1-(alpha-aminobenzyl)-2-naphthol. The reaction proceeds at room temperature in toluene with high diastereoselectivity. The major diastereomer can be separated by crystallization from an appropriate solvent. The relative configuration of both chiral centers of the major diastereomer was determined by single-crystal X-ray structure analysis. The desired alpha-aminophosphonic acids can be obtained in enantiopure form by treatment of the corresponding diastereomers with HCl.
Metlushka
Kirill E
KE
Kazan Scientific Center of the Russian Academy of Sciences, A. E. Arbuzov Institute of Organic and Physical Chemistry, Arbuzov str. 8, Kazan 420088, Russia.
Kashemirov
Boris A
BA
Zheltukhin
Viktor F
VF
Sadkova
Dilyara N
DN
Büchner
Bernd
B
Hess
Christian
C
Kataeva
Olga N
ON
McKenna
Charles E
CE
Alfonsov
Vladimir A
VA
D006851:Hydrochloric Acid / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry*; D063065:Organophosphonates / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
C542369:1-(alpha-aminobenzyl)-2-naphthol; D007097:Imines; D009284:Naphthols; D063065:Organophosphonates; D006851:Hydrochloric Acid