Enantio-Differentiating Hydrogenation of Methyl 2-Furoylacetate and Its Analogs over Tartaric Acid-Modified Raney Nickel
作者:Satoshi Nakagawa、Noriko Haruna、Delicia E. Acosta、Tadateru Endo、Takashi Sugimura、Akira Tai
DOI:10.1246/cl.1999.1055
日期:1999.10
Hydrogenation of methyl 2-furoylacetate over TA-MRNi reduced the three unsaturated bonds to give methyl tetrahydro-2-furoylacetate, the enantiomeric excess (ee) of which at the 3-position was 77%, whereas the 4-position was racemic. Under the same conditions, the substrate of 4-methoxycarbonyl analogue was resulted in hydrogenation of only the ketone moiety to give the corresponding chiral sec-alcohol
A process for producing a β-hydroxyester by reacting an epoxide, an alcohol and carbon monoxide in the presence of a cobalt carbonyl compound as catalyst,
which is characterized in using as co-catalyst, a pyridine derivative having an amino substituent of formula (1),
wherein R
1
and R
2
are independently hydrogen, formyl, acyl, alkoxycarbonyl, substituted or unsubstituted alkyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, or R
1
and R
2
may be taken together with the adjacent nitrogen atom to form a ring, and n is an integer of 1 or 2.
A process for producing a β-hydroxyester by reacting an epoxide, an alcohol and carbon monoxide in the presence of a cobalt carbonyl compound as catalyst,
which is characterized in using as co-catalyst, a pyridine derivative having an amino substituent of formula (1),
wherein R1 and R2 are independently hydrogen, formyl, acyl, alkoxycarbonyl, substituted or unsubstituted alkyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, or R1 and R2 may be taken together with the adjacent nitrogen atom to form a ring, and n is an integer of 1 or 2.
Asymmetric hydrogenation of keto esters using a BisP*-RuBr2, catalyst is reported. High enantioselectivities up to 98% were achieved in the hydrogenation of beta-keto esters. (C) 1999 Elsevier Science Ltd. All rights reserved.