Phosphine compounds, transition metal complexes thereof and use thereof as chiral hydrogenation catalysts
申请人:THE PROCTER & GAMBLE COMPANY
公开号:EP0036741A2
公开(公告)日:1981-09-30
The chiral phosphine ligand (R)-1,2-bis (diphenyiphosphi- no)-1-cyclohexylethane, when complexed to a transition metal such as Rh(l), functions as a superior chiral hydrogenation catalyst. The chiral phosphine ligand is more stereochemically rigid than previous compounds; consequently, virtually optically pure materials can be produced from the chiral hydrogenation of prochiral compounds using the catalyst of this invention. This catalyst is especially useful in the chiral hydrogenation of alpha-acylamido acrylic acids.
The first expedient entry to the human melanogen 2-S-cysteinyldopa exploiting the anomalous regioselectivity of 3,4-dihydroxycinnamic acid–thiol conjugation
作者:Lucia Panzella、Maria De Lucia、Alessandra Napolitano、Marco d’Ischia
DOI:10.1016/j.tetlet.2007.08.098
日期:2007.10
The first convenient synthesis of 2-S-cysteinyl-3,4-dihydroxyphenylalanine (2-S-cysteinyldopa) in 30% overall yield is reported, which capitalizes on the anomalous regiochemistry of the oxidative coupling of 3,4-dihydroxycinnamic acid derivatives with thiol compounds, leading to 2-S rather than the usual 5-S conjugates. (C) 2007 Elsevier Ltd. All rights reserved.