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Synthesis of Versatile Building Blocks through Asymmetric Hydrogenation of Functionalized Itaconic Acid Mono‐Esters
Author(s) -
Hekking Koen F. W.,
Lefort Laurent,
de Vries André H. M.,
van Delft Floris L.,
Schoemaker Hans E.,
de Vries Johannes G.,
Rutjes Floris P. J. T.
Publication year - 2008
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200700307
Subject(s) - chemistry , itaconic acid , rhodium , denticity , asymmetric hydrogenation , phosphoramidite , ligand (biochemistry) , succinic acid , carboxylic acid , combinatorial chemistry , alkyl , organic chemistry , catalysis , enantioselective synthesis , metal , copolymer , polymer , receptor , dna , biochemistry , oligonucleotide
Abstract The rhodium‐catalyzed asymmetric hydrogenation of several β‐substituted itaconic acid monoesters, using a library of monodentate phosphoramidite and phosphite ligands is described. Two β‐alkyl‐substituted substrates were readily hydrogenated by the rhodium complex Rh(COD) 2 BF 4 in combination with ( S )‐PipPhos as a ligand resulting in ee s of 99 %. In contrast, the corresponding more hindered β‐aryl‐substituted substrates did not exhibit acceptable enantioselectivities under these conditions. However, the use of a 48‐membered ligand library led to the identification of several suitable ligands for these substrates, resulting in ee s of 89–99 %. The resulting optically active succinic acid derivatives are potentially useful building blocks for more elaborate compounds, because of the ability to differentiate between the carboxylic acid and the ester groups on either side of the molecule.