(Salen)Ti(IV)-Catalyzed Asymmetric Ring-Opening of Monosubstituted Epoxides with Dithiophosphorus Acid

Publisher: Bentham Science Publishers

E-ISSN: 1875-6255|2|8|752-754

ISSN: 1570-1786

Source: Letters in Organic Chemistry, Vol.2, Iss.8, 2005-12, pp. : 752-754

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Abstract

The asymmetric ring-opening of monosubstituted epoxides with dithiophosphorus acids catalyzed by a (salen)Ti(IV) complex formed in situ from the reaction of Ti(OPr-i)4 and the chiral salen ligand derived from (1R,2R)-(+)-diaminocyclohexane and (R)-2,2'-diamino-1,1'- binaphthalene was realized. The resulting products were obtained with moderate enantioselectivity (up to 57% ee). High regioselectivity was observed for the alkyl substituted epoxides, whereas poor regioselectivity was obtained for the aryl substituted epoxides.