283151-88-2Relevant academic research and scientific papers
Asymmetric Catalytic Enantio- and Diastereoselective Boron Conjugate Addition Reactions of α-Functionalized α,β-Unsaturated Carbonyl Substrates
Xie, Jian-Bo,Lin, Siqi,Qiao, Shuo,Li, Guigen
, p. 3926 - 3929 (2016/08/16)
An efficient catalytic system has been established for the asymmetric boron conjugate addition of B2pin2 onto α-functionalized (involving C, N, O, and Cl) α,β-unsaturated carbonyls under mild, neutral conditions involving Cu[(S)-(R)-ppfa]Cl, AgNTf2, and alcohols. The dual additives of AgNTf2 and alcohols were found to play crucial roles for achieving high catalytic activity and enantio- and diastereoselectivity (up to 98% ee and 70:1 dr).
Cu-catalyzed chemoselective preparation of 2-(pinacolato)boron-substituted allylcopper complexes and their insitu site-, diastereo-, and enantioselective additions to aldehydes and ketones
Meng, Fanke,Jang, Hwanjong,Jung, Byunghyuck,Hoveyda, Amir H.
supporting information, p. 5046 - 5051 (2013/07/05)
Sustainable, efficient, selective: A three-component, single-vessel Cu-catalyzed method for chemo-, diastereo-, and enantioselective conversion of B2(pin)2, monosubstituted allenes, and aldehydes or ketones to 2-B(pin)-substituted homoallylic alkoxides is described. Subsequent functionalization delivers valuable products in up to >98:2 d.r. and 97:3 e.r. (see scheme). Copyright
Synthesis of an immunomodulator (+)-conagenin and its analogs
Yakura, Takayuki,Yoshimoto, Yuya,Ishida, Chisaki,Mabuchi, Shunsuke
, p. 4429 - 4438 (2008/02/02)
Stereoselective synthesis of an immunomodulator (+)-conagenin was achieved. Both amine and carboxylic acid moieties were prepared from commercially available optically active methyl 3-hydroxy-2-methylpropanoate using dirhodium(II)-catalyzed C-H amination
Stereoselective synthesis of an immunomodulator (+)-conagenin using dirhodium(II)-catalyzed C-H amination and chelation-controlled reductions as key steps
Yakura, Takayuki,Yoshimoto, Yuya,Ishida, Chisaki,Mabuchi, Shunsuke
, p. 930 - 932 (2007/10/03)
Stereoselective synthesis of an immunomodulator (+)-conagenin from commercially available optically active methyl 3-hydroxy-2-methylpropanoate was achieved using dirhodium(II)-catalyzed C-H amination and chelation-controlled reductions as key steps. Georg
A new roate to cationic half-sandwich ruthenium(II) complexes with chiral cyclopentadienylphosphane ligands
Doppiu, Angelino,Salzer, Albrecht
, p. 2244 - 2252 (2007/10/03)
Optically active cyclopentadieny-linked phosphane ligands Ln of general formula C5H5CH2CH(R) PR′2 (R = Ph, R′ = Ph, L1; R = Ph, R′ = Cy, L2; R = mesityl, R′ = Ph, L3)
Stereoselective aldol additions of achiral ethyl ketone-derived trichlorosilyl enolates
Denmark, Scott E.,Pham, Son M.
, p. 5045 - 5055 (2007/10/03)
Methods for the preparation of geometrically defined enoxy(trichlorosilanes) derived from ethyl ketone enolates have been developed. The addition of enoxy(trichlorosilanes) (trichlorosilyl enolates) to aldehydes proceeds with good yields in the presence of catalytic amounts of chiral phosphoramides. The reaction of Z-trichlorosilyl enolates to aryl aldehydes affords aldol products with good to excellent diastereo- and enantioselectivities. Phosphoramide-catalyzed aldol additions lacked substrate generality providing modest selectivities with unsaturated and aliphatic aldehydes. In all cases, the phosphoramide-catalyzed aldol addition of E-trichlorosilyl enolates to aldehydes provided good yields with moderate to good stereoselectivities.
Asymmetric aldol reactions using (S,S)-(+)-pseudoephedrine-based amides: Stereoselective synthesis of α-methyl-β-hydroxy acids, esters, ketones, and 1,3-syn and 1,3-anti diols
Vicario, Jose L.,Badia, Dolores,Dominguez, Esther,Rodriguez, Monica,Carrillo, Luisa
, p. 3754 - 3759 (2007/10/03)
A very efficient method for performing stereoselective aldol reactions is reported. The reaction of (S,S)-(+)-pseudoephedrine-derived propionamide enolates with several aldehydes yielded exclusively one of the four possible diastereomers in good yields, although transmetalation of the firstly generated lithium enolate with a zirconium(II) salt, prior to the addition of the aldehyde, is necessary in order to achieve high syn selectivity. The so-formed syn-α-methyl-β-hydroxy amides were transformed into other valuable chiral nonracemic synthons such as α-methyl-β-hydroxyacids, esters, and ketones. Finally, a stereocontrolled reduction procedure starting from the so-obtained α-methyl-β-hydroxy ketones has been developed allowing the synthesis of either 1,3-syn- or 1,3-anti-α-methyl-1,3-diols in almost enantiopure form by choosing the appropriate reaction conditions.
AN EFFICIENT ASYMMETRIC ALDOL REACTION OF 4-TRIMETHYLSILOXY-6-METHYLENE-1,3-DIOXINES BY CHIRAL BINAPHTHOL-TITANIUM COMPLEX CATALYSIS
Sato, Masayuki,Sunami, Satoshi,Sugita, Yoshiaki,Kaneko, Chikara
, p. 1435 - 1444 (2007/10/02)
The asymmetric aldol reaction of 4-trimethylsiloxy-6-methylene-1,3-dioxines or the 6-ethylidene analogue with achiral aldehydes proceeds in a highly enantioselective manner under chiral binaphthol-titanium complex catalysis to afford 6-substituted 1,3-dio
Regio-, Diastereo-,and Enantio-selective Condensation of Chiral Vinylic Borates with Aldehydes
Basile, Tiziana,Biondi, Stefano,Boldrini, Gian Paolo,Tagliavini, Emilio,Trombini, Claudio,Umani-Ronchi, Achille
, p. 1025 - 1029 (2007/10/02)
A regio- and diastereo-selective synthesis of enantiomerically enriched syn-ketols is reported, starting from homochiral 2-(but-2-en-2-yloxy)-1,3,2-dioxaborolanes and aldehydes.
