889130-06-7Relevant academic research and scientific papers
Enantioselective Synthesis of Chiral 3-Substituted-3-silylpropionic Esters via Rhodium/Bisphosphine-Thiourea-Catalyzed Asymmetric Hydrogenation
Zhang, Zongpeng,Han, Zhengyu,Gu, Guoxian,Dong, Xiu-Qin,Zhang, Xumu
supporting information, p. 2585 - 2589 (2017/08/16)
We have successfully developed the asymmetric hydrogenation of β-silyl-α,β-unsaturated esters to prepare chiral 3-substituted-3-silylpropionic ester products catalyzed by rhodium/bisphosphine-thiourea (ZhaoPhos) with excellent results (up to 97% yield, >99% ee, 1500 TON). Moreover, our hydrogenation products can be efficiently converted to other important organic molecules, such as chiral ethyl (R)-3-hydroxy-3-phenylpropanoate or (R)-3-[dimethyl(phenyl)silyl]-3-phenylpropanoic acid. (Figure presented.).
An Insoluble Copper(II) Acetylacetonate-Chiral Bipyridine Complex that Catalyzes Asymmetric Silyl Conjugate Addition in Water
Kitanosono, Taku,Zhu, Lei,Liu, Chang,Xu, Pengyu,Kobayashi, Shu
supporting information, p. 15422 - 15425 (2015/12/26)
Acicular purplish crystals were obtained from Cu(acac)2 and a chiral bipyridine ligand. Although the crystals were not soluble, they nevertheless catalyzed asymmetric silyl conjugate addition of lipophilic substrates in water. Indeed, the reactions proceeded efficiently only in water; they did not proceed well either in organic solvents or in mixed water/organic solvents in which the catalyst/substrates were soluble. This is in pronounced contrast to conventional organic reactions wherein the catalyst/substrates tend to be in solution. Several advantages of the chiral Cu(II) catalysis in water over previously reported catalyst systems have been demonstrated. Water is expected to play a prominent role in constructing and stabilizing sterically confined transition states and accelerating subsequent protonation to achieve high yields and enantioselectivities.
Chiral silanes via asymmetric hydrosilylation with catalytic CuH
Lipshutz, Bruce H.,Tanaka, Naoki,Taft, Benjamin R.,Lee, Ching-Tien
, p. 1963 - 1966 (2007/10/03)
CuH-catalyzed asymmetric conjugate reduction of β-silyl-α, β-unsaturated esters has been developed. Using PMHS as a stoichiometric source of hydride and in situ generated CuH ligated by Solvias' JOSIPHOS analogue PPF-P(t-Bu)2 leads to highly enantioselective 1,4-reductions.
