Homogeneous hydrogenation and isomerization reaction of cis-2-butene-1,4-diol has been investigated in ethanol by using tris(triphenylphosphine) chlororhodium(I), RhCl(PPh3)3, and triethylamine at 303 K and 0.01–0.1 MPa partial hydrogen pressure. Under reduced H2 pressure, the geometric isomerization reaction occurs, to a high extent, leading to trans-2-butene-1,4-diol up to 93% selectivity at 90% conversion of the cis analogous. Effects of H2 partial pressure as well as triethylamine, added phosphine and olefin concentrations on the rate of reaction and on the products distribution were also investigated. The results obtained can be interpreted on the basis of a proposed mechanism in which RhH(PPh3)3 is the active species. The high selectivity towards cis-trans isomerization of cis-2-butene-1,4-diol is attributed to steric factors of the Rh(I) coordinated triphenylphosphine groups.
Cis-trans isomerization of olefinic alcohols promoted by Rh(I) complexes” / Musolino, Maria Grazia; Apa, G.; Donato, A.; Pietropaolo, R.. - In: CATALYSIS TODAY. - ISSN 0920-5861. - 100:(2005), pp. 467-471. (Intervento presentato al convegno 11th Nordic Symposium on Catalysis tenutosi a Oulu (Finland) nel 23 – 25 maggio 2004) [10.1016/j.cattod.2004.10.031].
Cis-trans isomerization of olefinic alcohols promoted by Rh(I) complexes”
Maria Grazia MUSOLINO;G. APA;A. DONATO;R. PIETROPAOLO
2005-01-01
Abstract
Homogeneous hydrogenation and isomerization reaction of cis-2-butene-1,4-diol has been investigated in ethanol by using tris(triphenylphosphine) chlororhodium(I), RhCl(PPh3)3, and triethylamine at 303 K and 0.01–0.1 MPa partial hydrogen pressure. Under reduced H2 pressure, the geometric isomerization reaction occurs, to a high extent, leading to trans-2-butene-1,4-diol up to 93% selectivity at 90% conversion of the cis analogous. Effects of H2 partial pressure as well as triethylamine, added phosphine and olefin concentrations on the rate of reaction and on the products distribution were also investigated. The results obtained can be interpreted on the basis of a proposed mechanism in which RhH(PPh3)3 is the active species. The high selectivity towards cis-trans isomerization of cis-2-butene-1,4-diol is attributed to steric factors of the Rh(I) coordinated triphenylphosphine groups.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
