ISSN:
1572-9028
Schlagwort(e):
zeolite Beta
;
titanium–Beta
;
transition state selectivity
;
MPV–reduction
;
Oppenauer oxidation
;
enantioselective reduction
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract Zeolite Beta, in the Al–form as well as in the Al–free, Ti–containing form, appears to be a selective and regenerable catalyst in the Meerwein–Ponndorf–Verley and Oppenauer (MPVO) reactions. In the liquid–phase MPV reduction of 4–tert–butylcyclohexanone with secondary alcohols, both catalysts display a high stereoselectivity to cis–4–tert–butylcyclohexanol, the isomer of industrial relevance. This stereoselectivity can be explained by considering the two transition states inside the pores of zeolite Beta. By using (S)–2–butanol as the reductant enantioselective reduction of phenylacetone was observed. 4–methylcyclohexanone was studied as the substrate in the gas–phase MPV reduction. Catalyst deactivation is much more pronounced with the acidic Al–Beta catalyst than with the non–acidic Ti–Beta.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1019160827175
