chiral-phosphine-ligands| Page 26 of 630 | Chiral phosphine ligands

Wang, Dongqiang’s team published research in Journal of Separation Science in 38 | CAS: 297752-25-1

Journal of Separation Science published new progress about 297752-25-1. 297752-25-1 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is (R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide, and the molecular formula is C9H11BO4, Quality Control of 297752-25-1.

Wang, Dongqiang published the artcilePreparation and evaluation of novel chiral stationary phases based on quinine derivatives comprising crown ether moieties, Quality Control of 297752-25-1, the publication is Journal of Separation Science (2015), 38(2), 205-210, database is CAplus and MEDLINE.

The C9-position of quinine was modified by meta- or para-substituted benzo-18-crown-6, and immobilized on 3-mercaptopropyl-modified silica gel through the radical thiol-ene addition reaction. These two chiral stationary phases were evaluated by chiral acids, amino acids, and chiral primary amines. The crown ether moiety on the quinine anion exchanger provided a ligand-exchange site for primary amino groups, which played an important role in the retention and enantioselectivity for chiral compounds containing primary amine groups. These two stationary phases showed good selectivity for some amino acids. The complex interaction between crown ether and protonated primary amino group was studied by the addition of inorganic salts such as LiCl, NH₄Cl, NaCl, and KCl to the mobile phase. The resolution results showed that the simultaneous interactions between two function moieties (quinine and crown ether) and amino acids were important for the chiral separation

Referemce:
https://en.wikipedia.org/wiki/Phosphine_ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Bai, Jian-Fei’s team published research in Organic Letters in 22 | CAS: 929294-27-9

Organic Letters published new progress about 929294-27-9. 929294-27-9 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is R-3,3′-Bis(2,4,6-triisopropylphenyl)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate, and the molecular formula is C50H65O4P, Product Details of C50H65O4P.

Bai, Jian-Fei published the artcileOrganocatalytic Formal (3+2) Cycloaddition toward Chiral Pyrrolo[1,2-a]indoles via Dynamic Kinetic Resolution of Allene Intermediates, Product Details of C50H65O4P, the publication is Organic Letters (2020), 22(14), 5439-5445, database is CAplus and MEDLINE.

The chiral phosphoric acid catalyzed formal (3+2) cycloaddition of 3-substituted 1H-indoles and propargylic alcs. containing a functional directing group (p-NHAc or p-OH) was reported. A straightforward method to synthesize chiral pyrrolo[1,2-a]indole bearing a tetrasubstituted carbon stereocenter was represented. The reaction proceeded smoothly with a wide array of substrate tolerance to deliver various chiral pyrrolo[1,2-a]indoles in up to 93% yield and 98% ee. The utility of this method is highlighted by the diverse transformations of the products into various indole derivatives

Pan, Subhas Chandra’s team published research in Angewandte Chemie, International Edition in 46 | CAS: 929294-27-9

Angewandte Chemie, International Edition published new progress about 929294-27-9. 929294-27-9 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is R-3,3′-Bis(2,4,6-triisopropylphenyl)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate, and the molecular formula is C50H65O4P, Application In Synthesis of 929294-27-9.

Pan, Subhas Chandra published the artcileCatalytic asymmetric acylcyanation of imines, Application In Synthesis of 929294-27-9, the publication is Angewandte Chemie, International Edition (2007), 46(4), 612-614, database is CAplus and MEDLINE.

The less problematic acetyl cyanide was used instead of toxic HCN for the highly enantioselective acyl-Strecker-type reaction. In the presence of an N-benzylimine and a catalytic amount of chiral phosphoric acids or thioureas, the desired amidonitriles were obtained in excellent enantioselectivities and yields.

Cheng, Ke’s team published research in Chinese Journal of Chemistry in 29 | CAS: 297752-25-1

Chinese Journal of Chemistry published new progress about 297752-25-1. 297752-25-1 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is (R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide, and the molecular formula is C20H21O4P, HPLC of Formula: 297752-25-1.

Cheng, Ke published the artcileChiral phosphoric acid catalyzed enantioselective allylation of aldehydes with allyltrichlorosilane, HPLC of Formula: 297752-25-1, the publication is Chinese Journal of Chemistry (2011), 29(8), 1669-1671, database is CAplus.

Easily accessible chiral phosphoric acid 1b has been applied as efficient organocatalyst for the asym. allylation of aldehydes with allyltrichlorosilane. In the presence of 20 mol% of 1b, the allylation of a broad range of aldehydes proceeded smoothly to give the corresponding homoallylic alc. with up to 87% ee and 97% yield.

Hrdina, Radim’s team published research in Organometallics in 32 | CAS: 297752-25-1

Organometallics published new progress about 297752-25-1. 297752-25-1 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is (R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide, and the molecular formula is C20H21O4P, Formula: C20H21O4P.

Hrdina, Radim published the artcileSynthesis, Structural Analysis, and Catalytic Properties of Tetrakis(binaphthyl or octahydrobinaphthyl phosphate) Dirhodium(II,II) Complexes, Formula: C20H21O4P, the publication is Organometallics (2013), 32(2), 473-479, database is CAplus.

The x-ray structural analyses of homoleptic Rh(II) complexes made of enantiopure (R)-1,1′-binaphthyl and (R)-(5,5′,6,6′,7,7′,8,8′-octahydro)binaphthyl phosphate ligands are for the 1st time presented. The possibility to introduce halogen atoms at the 3,3′-positions is also reported. The isolated dirhodium complexes were further tested as catalysts (1 mol %) in enantioselective cyclopropanations and Si-H insertion reactions, affording chiral cyclopropanes and silanes in good yield but moderate enantioselectivity (ee maximum 63%).

Romanov-Michailidis, Fedor’s team published research in Angewandte Chemie, International Edition in 52 | CAS: 929294-27-9

Romanov-Michailidis, Fedor published the artcileEnantioselective Organocatalytic Fluorination-Induced Wagner-Meerwein Rearrangement, Formula: C50H65O4P, the publication is Angewandte Chemie, International Edition (2013), 52(35), 9266-9270, database is CAplus and MEDLINE.

The synthesis of the target compounds was achieved (optimized conditions) using 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane tetrafluoroborate(1-) (Selectfluor) as fluorination agent and a chiral dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin 4-oxide as catalyst. The title compounds thus formed included 3′,4′-dihydro-2′-(fluoro)spiro[cyclopentane-1,1′(2′H)-naphthalen]-2-one derivatives, 3′,4′-dihydro-2′-(fluoro)spiro[cyclobutane-1,1′(2′H)-naphthalen]-2-one derivatives and 3′,4′-dihydro-2′-(fluoro)spiro[cyclohexane-1,1′(2′H)-naphthalen]-2-one derivatives The title compounds thus formed included a chiral spiro[cyclobutane-naphthalenone] derivative (I). Reactants included 1-(3,4-dihydro-1-naphthalenyl)cyclobutanol, 1-(2H-1-benzopyran-4-yl)cyclobutanol, 1-(3,4-dihydro-1-naphthalenyl)cyclopentanol 1-(3,4-dihydro-1-naphthalenyl)cyclopropanol etc.

Romanov-Michailidis, Fedor’s team published research in Organic Letters in 15 | CAS: 929294-27-9

Romanov-Michailidis, Fedor published the artcileEnantioselective Organocatalytic Iodination-Initiated Wagner-Meerwein Rearrangement, COA of Formula: C50H65O4P, the publication is Organic Letters (2013), 15(22), 5890-5893, database is CAplus and MEDLINE.

The present manuscript describes a high-yielding enantioselective semipinacol transposition, initiated by an electrophilic iodination event. The title transformation makes use of the anionic phase-transfer catalysis (PTC) paradigm for chirality induction. Thus, when combined appropriately, the insoluble cationic iodinating reagent and the lipophilic phosphoric acid act as an efficient source of chiral iodine that performs the semipinacol transposition of strained allylic alcs. to β-iodo spiroketones in good yields and with high levels of diastereo- and enantio-induction. The product β-iodo spiroketones could be derivatized stereospecifically and without stereoerosion, giving rise to products inaccessible directly from a semipinacol rearrangement.

Furuno, Hiroshi’s team published research in Tetrahedron in 59 | CAS: 297752-25-1

Tetrahedron published new progress about 297752-25-1. 297752-25-1 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is (R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide, and the molecular formula is C20H21O4P, HPLC of Formula: 297752-25-1.

Furuno, Hiroshi published the artcileChiral rare earth organophosphates as homogeneous Lewis acid catalysts for the highly enantioselective hetero-Diels-Alder reactions, HPLC of Formula: 297752-25-1, the publication is Tetrahedron (2003), 59(52), 10509-10523, database is CAplus.

Various trivalent rare earth chiral phosphate complexes [ML₃] (L = I or II, R = H, 2,6-xylyl; M = Sc, La, Ce, Nd, Gd, Ho, Y) were prepared and evaluated as a Lewis acid catalyst for the asym. hetero-Diels-Alder reaction of aldehydes with the Danishefsky’s diene. Some of them effectively promoted the reaction at room temperature in the presence or absence of achiral additives under homogeneous conditions to afford the corresponding cycloadducts with high ee’s (up to 99% ee). During these reactions, remarkably high asym. amplifications (pos. nonlinear effects) were observed as the first example in the metal ion-chiral ligand 1:3 catalytic system. A scandium catalyst bearing the H₈-BNP ligand, [ScL₃] (L = II), could be recovered after the reaction and successfully reused for the next round of reactions. In addition, the hetero-Diels-Alder reaction of α-keto esters was effectively catalyzed by [YL₃] (L = I, R = H) without any additives thus producing the asym. quaternary carbon in excellent enantioselectivities (up to >99% ee).

He, Shanshan’s team published research in Chirality in 30 | CAS: 297752-25-1

Chirality published new progress about 297752-25-1. 297752-25-1 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is (R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide, and the molecular formula is C20H21O4P, SDS of cas: 297752-25-1.

He, Shanshan published the artcileNovel chiral ionic liquids stationary phases for the enantiomer separation of chiral acid by high-performance liquid chromatography, SDS of cas: 297752-25-1, the publication is Chirality (2018), 30(5), 670-679, database is CAplus and MEDLINE.

Novel chiral ionic liquid stationary phases based on chiral imidazolium were prepared The ionic liquid chiral selector was synthesized by ring opening of cyclohexene oxide with imidazole or 5,6-dimethylbenzimidazole, and then chem. modified by different substitute groups. Chiral stationary phases were prepared by bonding to the surface of silica sphere through thioene “click” reaction. Their enantioselective separations of chiral acids were evaluated by high-performance liquid chromatog. The retention of acid sample was related to the counterion concentration and showed a typical ion exchange process. The chiral separation abilities of chiral stationary phases were greatly influenced by the substituent group on the chiral selector as well as the mobile phase, which indicated that, besides ion exchange, other interactions such as steric hindrance, π-π interaction, and hydrogen bonding are important for the enantioselectivity. In this report, the influence of bulk solvent components, the effects of varying concentration, and the type of the counterion as well as the proportion of acid and basic additives were investigated in detail.

Xia, Zilei’s team published research in Organic Letters in 18 | CAS: 929294-27-9

Xia, Zilei published the artcileEnantioselective Bromo-oxycyclization of Silanol, SDS of cas: 929294-27-9, the publication is Organic Letters (2016), 18(1), 80-83, database is CAplus and MEDLINE.

Relying on the nucleophilicity of silanol for building up silicon-incorporated scaffold with an enantiopure tetrasubstituted carbon center remains elusive. In this report, asym. bromo-oxycyclization of olefinic silanol by using chiral anionic phase-transfer catalyst is described. This protocol provided a facile entry to a wide arrangement of enantiopure benzoxasilole in moderate to excellent enantioselectivities depending on the unique reactivity of bromine/N-benzyl-DABCO complex.