- Cinchona alkali ligand and preparation method and application thereof
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The invention belongs to the field of organic chemical ligands, and particularly relates to a cinchona alkali ligand, which has a structure shown in a general formula I or a tautomer, an enantiomer and a diastereoisomer thereof, in the formula I, R1 is selected from alkyl, alkenyl and -CH = CHPh, R2 is selected from hydrogen, alkyl, phenyl and substituted phenyl, and R is selected from substituted phenyl. The invention also discloses a preparation method and application of the cinchona alkaloid ligand. The ligand disclosed by the invention has advantages in stereoselectivity and reaction efficiency, and a higher ee value and yield can be obtained in an asymmetric reaction.
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Paragraph 0085-0087; 0089; 0093-0096; 0128-0129; 0134; ...
(2021/12/31)
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- Synthesis method of di(3,5-dimethylphenyl)phosphine
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The invention discloses a synthesis method of di(3,5-dimethylphenyl)phosphine. The synthesis method comprises the following steps: stirring and dissolving di(3,5-dimethylphenyl)phosphine oxide and toluene to obtain a solution A; under the protection of ar
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Paragraph 0022-0031
(2020/04/17)
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- METHODS FOR PREPARING BIS-TETRAHYDROISOQUINOLINE-CONTAINING COMPOUNDS
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(-)-Jorumycin, ecteinascidin 743, saframycin A and related compounds, methods of preparing the same, formulations comprising the compounds, and methods of treating proliferative diseases with the same are provided.
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Page/Page column 92; 93
(2019/02/06)
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- Synthesis and Characterization of Manganese(I) Carbonyl Complexes of the Type [(OC)4Mn{μ-P(R)Aryl}]2
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Metalation of secondary phosphanes HPRR′ [R = R′ = C6H4-4-Me, C6H3-3,5-Me2 (3), C6H4-4-NMe2 (4); R/R′ = Ph/cHex] with Mn2(CO)10 in boiling xylene
- Mede, Ralf,Blohm, Sascha,G?rls, Helmar,Westerhausen, Matthias
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supporting information
p. 508 - 514
(2016/04/19)
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- General and selective copper-catalyzed reduction of tertiary and secondary phosphine oxides: Convenient synthesis of phosphines
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Novel catalytic reductions of tertiary and secondary phosphine oxides to phosphines have been developed. Using tetramethyldisiloxane (TMDS) as a mild reducing agent in the presence of copper complexes, PO bonds are selectively reduced in the presence of other reducible functional groups (FGs) such as ketones, esters, and olefins. Based on this transformation, an efficient one pot reduction/phosphination domino sequence allows for the synthesis of a variety of functionalized aromatic and aliphatic phosphines in good yields.
- Li, Yuehui,Das, Shoubhik,Zhou, Shaolin,Junge, Kathrin,Beller, Matthias
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scheme or table
p. 9727 - 9732
(2012/07/14)
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- Highly chemoselective metal-free reduction of phosphine oxides to phosphines
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Unprecedented chemoselective reductions of phosphine oxides to phosphines proceed smoothly in the presence of catalytic amounts of specific Br?nsted acids. By utilizing inexpensive silanes, e.g., PMHS or (EtO)2MeSiH, other reducible functional groups such as ketones, aldehydes, olefins, nitriles, and esters are well-tolerated under optimized conditions.
- Li, Yuehui,Lu, Liang-Qiu,Das, Shoubhik,Pisiewicz, Sabine,Junge, Kathrin,Beller, Matthias
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p. 18325 - 18329
(2013/01/15)
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- Stereoelectronic factors in iron catalysis: Synthesis and characterization of aryl-substituted iron(II) carbonyl P-N-N-P complexes and their use in the asymmetric transfer hydrogenation of ketones
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A series of five (S,S)-trans-[Fe(CO)(Br)(PR2-CH 2CH=NCH(Ph)CH(Ph)N=CHCH2-PR2)][X] compounds (1a-c, X = BPh4; 1d,e, X = BF4) were synthesized and tested for the asymmetric transfer hydrogena
- Sues, Peter E.,Lough, Alan J.,Morris, Robert H.
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scheme or table
p. 4418 - 4431
(2011/10/10)
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- Catalyst-free alcoholysis of phosphane-boranes: a smooth, cheap, and efficient deprotection procedure
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Catalyst-free alcoholytic deprotection of borane-protected phosphorus compounds offers a smooth, efficient, and clean alternative to existing deprotection methods. In this paper we report our results on the general applicability of deprotecting phosphane-
- Van Overschelde, Michel,Vervecken, Elias,Modha, Sachin G.,Cogen, Simon,Van der Eycken, Erik,Van der Eycken, Johan
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experimental part
p. 6410 - 6415
(2009/12/09)
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- A METHOD FOR GENERATING SECONDARY PHOSPHINES
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This invention provides a method for generating secondary phosphines from secondary phosphine oxides in the presence of a reducing agent, such as diisobutylaluminum hydride (DIBAL-H), triisobutyldialuminoxane, triisobutylaluminum, tetraisobutyldialuminoxane, or another reducing agent comprising: (i) an R1R2AIH moiety, wherein R1 and R2 are each an alkyl species or oxygen, and wherein at least one of R1 or R2 comprises at least 2 carbon atoms, or (ii) an R1R2R3AI moiety, wherein R1, R2, and R3 are not hydrogen, and wherein at least one of R1, R2, and R3 is an alkyl species comprising a β-hydrogen, not including triethylaluminum. Preferred reducing agents for the present invention include: diisobutylaluminum hydride, triisobutyldialiuminoxane, triisobutylaluminum, tetraisobutyldialuminoxane, and combinations thereof.
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Page/Page column 12-13
(2008/06/13)
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- Chiral Xyliphos Complexes for the Catalytic Imine Hydrogenation Leading to the Metolachlor Herbicide: Isolation of Catalyst-Substrate Adducts
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Iridium complexes relevant to the catalytic enantioselective hydrogenation of 2-methyl-6-ethylphenyl-1′-methyl-2′-methoxyethylimine (MEA-imine, 1) in the Syngenta Metolachlor (3) process were prepared and characterized. Reaction of the diphosphane (S)-1-[(R)-2-(diphenylphosphanyl)ferrocenyl]ethyldi(3,5-xylyl)phosphane ((S)-(R)-Xyliphos, (S)-(R)-4) with [Ir2(μ-Cl) 2(cod)2] (cod = 1,5-cyclooctadiene) afforded [Ir(Cl)(cod){(S)-(R)-4}] (7), which reacted with AgBF4 to form [Ir(cod){(S)-(R)-4}]BF4 (8). Complexes 7 and 8 reacted with iodide to yield [Ir(I)(cod){(S)-(R)-4}] (9). When 9 was treated with one and two equivalents of HBF4, two isomers of the cationic IrIII iodo hydrido complex [Ir(I)(H)-(cod){(S)-(R)-4}]BF4 were isolated (10 and 11, respectively). Complex 9 was oxidized with one equivalent of I2 to give the iodo-bridged dinuclear species [Ir 2I2(μ-I)3{(S)-(R)-4}2)] I (12). [Ir2(μ-Cl)2(coe)4] (coe=cyclooctene) reacted with (S)-(R)4 to yield the chlorobridged dinuclear complex [Ir2(μ-Cl)2{(S)-(R)-4}2] (13). Complexes 7-12 were structurally characterized by single-crystal X-ray diffraction and tested as single-component catalyst precursors for enantioselective hydrogenation of MEA-imine. Complex 10 and dinuclear complex 12 gave the best catalytic results. Efforts were also directed at isolating substrate- or product-catalyst adducts: Treatment of 8 with 2,6-dimethylphenyl-1′-methyl-2′-methoxyethylimine (DMA-imine, 14, a model for 1) under H2 allowed four isomers of [Ir(H) 2{(S)-(R)-4}(14)]BF4 (18-21) to be isolated. These analytically pure isomers were fully characterized by 2D NMR techniques. X-ray structural analysis of an IrI-imine adduct, namely, [Ir(C 2H4)2(14)]BF4 (25), which was prepared by reacting [IrCl(C2H4)4] with [Ag(14)2]BF4 (16), confirmed the κ2 coordination mode of imine 14.
- Dorta, Romano,Broggini, Diego,Stoop, Robert,Rueegger, Heinz,Spindler, Felix,Togni, Antonio
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p. 267 - 278
(2007/10/03)
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- An expedient reduction of sec-phosphine oxides to sec-phosphine-boranes by BH3·SMe2
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Secondary phosphine oxides can be expeditiously converted into secondary phosphine-boranes by treatment with an excess of BH3·SMe2 at room temperature. Selectivity of the conversion towards the formation of secondary phosphine-boranes is greatly improved by the addition of a small amount of water to the reaction mixture.
- Stankevi?, Marek,Pietrusiewicz, K. Micha?
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p. 1012 - 1016
(2007/10/03)
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- Synthesis of achiral, but unsymmetric, seven-membered rhodium(I)-chelates for hydrogenation in the chiral environment of alkyl polyglucoside micelles
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Chiral rhodium(I) chelates containing a seven-membered ring are well-known active catalysts for the asymmetric hydrogenation of amino acid precursors. A high conformational flexibility allows their enantioselectivity to be strongly influenced by modifiers. Now we show the nature of the counter-ions to have a large influence in apolar solvents. In addition, the presence of micelle forming alkyl polyglycosides as amphiphiles causes a remarkable increase in the enantiomeric excess (%ee). However, on achiral catalysts this enantioselectivity inducing effect scarcely exceeds the standard deviation for the gas chromatographic determination of the enantiomeric ratio. This is also true for the application of unsymmetric P,P′-ligands such as 3-phosphinopropyl-phosphinites or butane-1,4-diyl-bis(phosphines) carrying different P′-aryl groups, for which synthetic routes are given.
- Fehring,Kadyrov,Ludwig,Holz,Haage,Selke
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p. 120 - 129
(2007/10/03)
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