Erschienen in:
European Journal of Organic Chemistry, 2010 (2010) 1, Seite 157-167
Sprache:
Englisch
DOI:
10.1002/ejoc.200901099
ISSN:
1434-193X;
1099-0690
Entstehung:
Anmerkungen:
Beschreibung:
AbstractA new series of α‐ and β‐cyclodextrin derivatives containing a substituted amino–acetone bridge attached to the 6A and 6D positions of the cyclodextrin are reported. The synthesis starts from the known α‐ or β‐cyclodextrin A,D‐diols, which were either oxidized to α‐ or β‐cyclodextrin A,D‐dicarbaldehydes and then coupled with 1,3‐diamino‐2‐propanol by a reductive amination reaction and further modified to give the final 6A,6D‐diamino‐6A,6D‐dideoxy‐N,N′‐(2‐oxopropa‐1,3‐dienyl)‐N,N′‐acetyl‐α‐ or ‐β‐cyclodextrin or the cyclodextrin‐diol was substituted with azide then reduced and after a few alkylation steps the final 6A,6D‐dideoxy‐N,N′‐(2‐oxopropa‐1,3‐dienyl)‐6A,6D‐(N,N,N′N′‐tetramethyldiammonio)‐α‐cyclodextrin dibromide was obtained. The new compounds display very good enzymatic catalytic properties in the oxidation of benzyl alcohols with a rate increase of up to 18500 but only appreciable catalysis for aniline oxidations. Thus, unlike previously studied cyclodextrin ketones, these new amino–acetone‐bridged cyclodextrins have high substrate selectivity and also exhibit stereoselectivity in the oxidation of different enantiomers.