153221-16-0Relevant 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
, 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.).
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.
Diastereoselectivity in the Preparation of β-Silyl Esters from αβ-Unsaturated Esters and Amides Attachhed to Chiral Auxiliaries
Fleming, Ian,Kindon, Nicolas D.
, p. 303 - 316 (2007/10/02)
The conjugate addition of the phenyldimethylsilyl-cuprate reagent to cinnamate and crotonate esters and amides 1 of various known chiral auxiliaries, a-e, is diastereoselective.The sense of diastereoselectivity of silyl-cuprate addition to the esters 1b-d, 8 and 9 is different from established precedent based on carbon-cuprates, but is normal for silyl-cuprate addition to the amide 1a, the imines 1e and 21, and the oxazolidine 6.The chiral auxiliary e gives the best results of those tested, and the silicon-containing group can be removed from the chiral auxiliary using alkoxide ion in aprotic media, making available β-silyl esters 27-29 of high enantiomeric excess, with recovery of the chiral auxiliary 30.
Dispiroketals in synthesis (Part 16): Functionalised dispiroketals as new chiral auxiliaries; the synthesis of dihydroxylated dispiroketals in optically pure form and their application as bifunctional , C2-symmetrical, chiral auxiliaries for highly stereoselective Michael additions
Bezuidenhoudt, Barend C. B.,Castle, Grant H.,Innes, Jean E.,Ley, Steven V.
, p. 184 - 194 (2007/10/02)
A range of rigid, architecturally complex diols derived from dispiroketals have been synthesised.A bifunctional, C2-symmetrical, chiral auxiliary derived from these dihydroxylated dispiroketals has been used to induce a high degree of asymmetry in Michael additions of cuprates to a variety of di-α,β-unsaturated ester systems.
Dispiroketals in Synthesis (Part 14): Functionalised Dispiroketals as New Chiral Auxiliaries; Highly Stereoselective Michael Additions to a Bifunctional, C2-Symmetrical Chiral Auxiliary.
Castle, Grant H.,Ley, Steven V.
, p. 7455 - 7458 (2007/10/02)
A bifunctional, C2-symmetrical chiral auxiliary derived from dihydroxylated dispiroketals has been used to induce a high degree of asymmetry in Michael additions of cuprates to a variety of di-α,β-unsaturated ester systems.
