18890-22-7Relevant academic research and scientific papers
Enantioselective hydride transfer hydrogenation of ketones catalyzed by [(η6-p-cymene)Ru(amino acidato)Cl] and [(η6-p-cymene)Ru(amino acidato)]3(BF4)3 complexes
Kathó, ágnes,Carmona, Daniel,Viguri, Fernando,Remacha, Carlos D.,Kovács, J.ózsef,Joó, Ferenc,Oro, Luis A.
, p. 299 - 306 (2000)
The new complexes (RRuSC, SRuSC)-[(η6-pCym)Ru(L-Aze)Cl] (6a, b), (RRuSC, SRuSC)-[(η6-pCym)Ru(L-Pip)Cl] (7a, b), (RRuRRuRRuSCSCSCSNSNSN, SRuSRuSRuSCSCSCSNSNSN)-[{(η6-pCym)Ru(L-Aze)}3](BF4)3 (8a, b) and (RRuRRuRRuSCSCSCSNSNSN, SRuSRuSRuSCSCSCSNSNSN)-[{(η6-pCym)Ru(L-Pip)}3](BF4)3 (9a, b) (L-Aze=L-2-azetidinecarboxylate, L-Pip=L-2-piperidinecarboxylate) were prepared, characterized and used, together with the known [{(η6-pCym)Ru(L-Pro)}3](BF4)3, 5 and [{(η6-pCym)Ru(L-Ala)}3](BF4)3, 10 (L-Pro=L-prolinate, L-Ala=L-alaninate), in hydride transfer reduction of acetophenone, a series of substituted acetophenones and several other ketones with moderate to high conversions and enantioselectivities up to 86% e.e.
Kinetic resolution strategies I: Enhanced product enantiomeric excesses and yields in sharpless epoxidations
Brown,Davies,De Sousa
, p. 511 - 514 (1991)
The process of kinetic resolution has been considered with the aim of optimising yields and enantiomeric excesses of optically active products. Double kinetic resolution techniques can show significant advantages in these respects over single step process
Development of a practical multikilogram production of (R)-seudenol by enzymatic resolution
Ter Halle,Bernet,Billard,Bufferne,Carlier,Delaitre,Flouzat,Humblot,Laigle,Lombard,Wilmouth
, p. 283 - 286 (2004)
Different enzymatic routes for the production of (R)-seudenol were investigated. The Novozym 435-catalyzed reaction of racemic seudenol with vinyl butyrate proved to be the most promising route. By using vinyl laurate as an acyl donor, (R)-seudenol laurat
Regio- And Stereoselective Addition of HO/OOH to Allylic Alcohols
Wang, Xiao-Tao,Han, Wei-Bo,Chen, Hui-Jun,Zha, Qinghong,Wu, Yikang
, p. 10007 - 10021 (2020/08/28)
A range of allylic alcohols are shown to readily react with ethereal H2O2 in the presence of catalytic amounts of Na2MoO4-gly or MoO2(acac)2, affording the C═C trans hydroxylation-hydroperoxylation products in good yields with high regio- and stereoselect
Stereoselective anti -S N 2′-Substitutions of Secondary Alkylcopper-Zinc Reagents with Allylic Epoxides: Total Synthesis of (3 S,6 R,7 S)-Zingiberenol
Kicin, Bilal,Knochel, Paul,Kremsmair, Alexander,Ruf, Vincent,Saeb, Rakan,Skotnitzki, Juri
, p. 873 - 881 (2020/03/13)
Chiral secondary mixed alkylcopper-zinc reagents were prepared from the corresponding alkyl iodides and reacted with allylic epoxides via an anti -S N 2′-substitution and retention of configuration of the chiral alkylorganometallic, leading to
Enantioselective Hydrogenation of Ketones using Different Metal Complexes with a Chiral PNP Pincer Ligand
Garbe, Marcel,Wei, Zhihong,Tannert, Bianca,Spannenberg, Anke,Jiao, Haijun,Bachmann, Stephan,Scalone, Michelangelo,Junge, Kathrin,Beller, Matthias
supporting information, p. 1913 - 1920 (2019/03/13)
The synthesis of different metal pincer complexes coordinating to the chiral PNP ligand bis(2-((2R,5R)-2,5-dimethyl-phospholanoethyl))amine is described in detail. The characterized complexes with Mn, Fe, Re and Ru as metal centers showed good activities regarding the reduction of several prochiral ketones. Comparing these catalysts, the non-noble metal complexes produced best selectivities not only for aromatic substrates, but also for different kinds of aliphatic ones leading to enantioselectivities up to 99% ee. Theoretical investigations elucidated the mechanism and rationalized the selectivity. (Figure presented.).
CHIRAL METAL COMPLEX COMPOUNDS
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Page/Page column 18; 19; 21; 23; 24; 29, (2018/11/10)
The invention comprises novel chiral metal complex compounds of the formula (I) wherein M, PR2, R3 and R4 are outlined in the description, its stereoisomers, in the form as a neutral complex or a complex cation with a suitable counter ion. The chiral metal complex compounds can be used in asymmetric reactions, particularly in asymmetric reductions of ketones, imines or oximes.
Manganese(I)-Catalyzed Enantioselective Hydrogenation of Ketones Using a Defined Chiral PNP Pincer Ligand
Garbe, Marcel,Junge, Kathrin,Walker, Svenja,Wei, Zhihong,Jiao, Haijun,Spannenberg, Anke,Bachmann, Stephan,Scalone, Michelangelo,Beller, Matthias
supporting information, p. 11237 - 11241 (2017/09/02)
A new chiral manganese PNP pincer complex is described. The asymmetric hydrogenation of several prochiral ketones with molecular hydrogen in the presence of this complex proceeds under mild conditions (30–40 °C, 4 h, 30 bar H2). Besides high catalytic activity for aromatic substrates, aliphatic ketones are hydrogenated with remarkable selectivity (e.r. up to 92:8). DFT calculations support an outer sphere hydrogenation mechanism as well as the experimentally determined stereochemistry.
Efficient Synthesis of Anastrephin via the Allylic Substitution for Quaternary Carbon Construction
Wada, Kyohei,Sakai, Masahiro,Kawashima, Hidehisa,Ogawa, Narihito,Kobayashi, Yuichi
, p. 1428 - 1432 (2016/05/24)
Lactone-moiety-attached 2-cyclohexylideneethyl picolinate was prepared through the OH-directed epoxidation (98% ds) of (R)-3-methylcyclohex-2-en-1-ol (99% ee), Horner-Wadsworth-Emmons olefination, conversion to the allylic moiety, and epoxide ring opening
Synthesis of chiral building blocks for oxygenated terpenoids through a simultaneous and stereocontrolled construction of contiguous quaternary stereocenters by an ireland-claisen rearrangement
Akahori, Yoshihiro,Yamakoshi, Hiroyuki,Sawayama, Yuki,Hashimoto, Shunichi,Nakamura, Seiichi
, p. 720 - 735 (2014/04/03)
Methods for highly stereocontrolled syntheses of chiral building blocks with a triad of contiguous stereocenters, including two quaternary ones, have been developed. Ireland-Claisen rearrangement of the (Z)-silyl ketene acetal generated stereoselectively
