A number of 3-O-substituted 1,3-dihydroxypropan-2-ones have been synthesized in view of their potential use as prochiral precursors of optically active glycerols. Indeed, the oxo-ethers have been reduced to the corresponding 3-O-substituted glycerols via chiral Ru complexes derived from (S)-binap, ( = (-)-(S)-2,2'-bis(diphenylphosphino)-1,1'-binaphthalene) with enantiomeric excesses up to 93%. The steric course or the catalytic reduction appears to be essentially dependent on the steric encumbrance or the substituents; indeed, a dramatic increase of the enantiomeric excess is observed when the bulky trityl group is substituted by the less encumbering benzyl or octadecyl groups.
Synthesis and ruthenium catalyzed enantioselective hydrogenation of 1,3-dihydroxypropan-2-one 1-ethers / E. Cesarotti, P. Antognazza, M. Pallavicini, L. Villa. - In: HELVETICA CHIMICA ACTA. - ISSN 0018-019X. - 76:6(1993), pp. 2344-2349. [10.1002/hlca.19930760620]
Synthesis and ruthenium catalyzed enantioselective hydrogenation of 1,3-dihydroxypropan-2-one 1-ethers
E. CesarottiPrimo
;M. PallaviciniPenultimo
;
1993
Abstract
A number of 3-O-substituted 1,3-dihydroxypropan-2-ones have been synthesized in view of their potential use as prochiral precursors of optically active glycerols. Indeed, the oxo-ethers have been reduced to the corresponding 3-O-substituted glycerols via chiral Ru complexes derived from (S)-binap, ( = (-)-(S)-2,2'-bis(diphenylphosphino)-1,1'-binaphthalene) with enantiomeric excesses up to 93%. The steric course or the catalytic reduction appears to be essentially dependent on the steric encumbrance or the substituents; indeed, a dramatic increase of the enantiomeric excess is observed when the bulky trityl group is substituted by the less encumbering benzyl or octadecyl groups.Pubblicazioni consigliate
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