15822-99-8Relevant academic research and scientific papers
Synthesis of versatile building blocks through asymmetric hydrogenation of functionalized itaconic acid mono-esters
Hekking, Koen F. W.,Lefort, Laurent,De Vries, Andre H. M.,Van Delft, Floris L.,Schoemaker, Hans E.,De Vries, Johannes G.,Rutjes, Floris P. J. T.
, p. 85 - 94 (2008)
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-alkylsubstituted substrates were readily hydrogenated by the rhodium complex Rh(COD) 2BF4 in combination with (S)-PipPhos as a ligand resulting in ees of 99 %. In contrast, the corresponding more hindered β-arylsubstituted 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 ees 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.
Catalytic asymmetric alkynylation and arylation of aldehydes by an H 8-binaphthyl-based amino alcohol ligand
Ruan, Jiwu,Lu, Gui,Xu, Lijing,Li, Yue-Ming,Chan, Albert S. C.
experimental part, p. 76 - 84 (2009/04/11)
A novel chiral H8-1,1'-binaphthyl-based amino alcohol ligand (1Ra,2S,3R)-2 has been synthesized and applied in the direct nucleophilic addition of organozincs (alkynylzinc and arylzinc prepared in situ) to aldehydes, yielding the corresponding optically active propargylic alcohols and diarylmethanols in high yields and good to excellent enantioselectivities. For the asymmetric arylation reaction, one catalyst (1Ra,2S,3R)-2 can afford both enantiomers of many pharmaceutically interesting diarylmethanols by a proper combination of various arylzinc reagents and aldehydes.
