57403-74-4Relevant articles and documents
Neutral iridium catalysts with chiral phosphine-carboxy ligands for asymmetric hydrogenation of unsaturated carboxylic acids
Yang, Shuang,Che, Wen,Wu, Hui-Ling,Zhu, Shou-Fei,Zhou, Qi-Lin
, p. 1977 - 1980 (2017/03/09)
We developed neutral iridium catalysts with chiral spiro phosphine-carboxy ligands (SpiroCAP) for asymmetric hydrogenation of unsaturated carboxylic acids. Different from the cationic Crabtree-type catalysts, the iridium catalysts with chiral spiro phosphine-carboxy ligands are neutral and do not require the use of a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF?) counterion, which is necessary for stabilizing cationic Crabtree-type catalysts. Another advantage of the neutral iridium catalysts is that they have high stability and have a long lifetime in air. The new iridium catalysts with chiral spiro phosphine-carboxy ligands exhibit unprecedented high enantioselectivity (up to 99.4% ee) in the asymmetric hydrogenations of various unsaturated carboxylic acids, particularly for 3-alkyl-3-methylenepropionic acids, which are challenging substrates for other chiral catalysts.
The 1,4-addition of organometallic reagents to enoates derived from pinanediol
Pinheiro, Sergio,Pedraza, Sergio F.,Peralta, Monica A.,Teixeira, Rafael C.,De Farias, Florence M. C.,Ferreira, Vitor F.,Costa, Paulo R. R.
, p. 2513 - 2517 (2007/10/03)
The complex-induced, proximity effect-promoted 1,4-addition of RCu·BF3 and R2CuLi to enoates derived from (-)-pinanediol leads to adducts with the opposite sense of chirality (up to 98% d.e.).
Enantioselective carbolithiation of β-alkylated styrene
Norsikian, Stephanie,Marek, Ilane,Normant, Jean-F.
, p. 7523 - 7526 (2007/10/03)
Stoichiometric or catalytic amounts of (-) sparteine serve as promoter for enantioselective carbolithiation of β-alkylated, non functionalized styrene.