Tag: M.W=600-700

Tanielyan, Setrak K.; Marin, Norman; Alvez, Gabriela; Augustine, Robert L. published the artcile< Two Efficient Enantioselective Syntheses of 2-Amino-1-phenylethanol>, HPLC of Formula: 325168-88-5, the main research area is aminophenylethanolstereoselective preparation.

Two enantioselective methods for the synthesis of 2-amino-1-phenylethanol have been developed. The first uses an enantioselective oxazaborolidine-catalyzed borane reduction of 2-chloroacetophenone (phenacyl chloride) to give the chiral chloro alc. in good yield with an ee in the 93-97% range. Reaction with dilute ammonium hydroxide produced the amino alc. in good yield with a high ee. The second approach involved the conversion of phenacyl chloride to the succinimidoacetophenone which was then hydrogenated using a chiral ruthenium complex in conjunction with a base and an optically active amine (Noyori procedure). This gave the optically active succinimido alc. in very good yield with an ee of 98%. Hydrolysis with dilute base produced the optically active amino alc. in very good yield and excellent enantioselectivity.

Organic Process Research & Development published new progress about 325168-88-5. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, HPLC of Formula: 325168-88-5.

Referemce:
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

Tindall, Daniel J.; Mader, Steffen; Kindler, Alois; Rominger, Frank; Hashmi, A. Stephen K.; Schaub, Thomas published the artcile< Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses>, Synthetic Route of 139139-86-9, the main research area is stereoselective hydrogenation catalyst catalysis alditol monosaccharide ketose; asymmetric catalysis; hydrogenation; industrial chemistry; ruthenium; sugar alcohol.

Sugar alcs. are of great importance for the food industry and are promising building blocks for bio-based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on com. available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi-gram scale allowing sugar alcs. to be isolated in large quantities at high atom economy.

Angewandte Chemie, International Edition published new progress about Alditols Role: SPN (Synthetic Preparation), PREP (Preparation). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Synthetic Route of 139139-86-9.

Referemce:
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

Hayashi, Tamio; Kawai, Masahiro; Tokunaga, Norihito published the artcile< Asymmetric synthesis of diarylmethyl amines by rhodium-catalyzed asymmetric addition of aryl titanium reagents to imines>, Name: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is arylsulfonyl arylimine aryltitanium asym addition rhodium; arylamine arylsulfonyl stereoselective preparation desulfonylation; amine diarylmethyl stereoselective preparation.

Rhodium/chiral phosphine-catalyzed asym. addition of aryltitanium triisopropoxides to N-arylidene sulfonamides (Ar1CH=NSO2Ar2) yielded diarylmethyl arylsulfonamides, e.g., I, enantioselectively. A rational tuning of the arene sulfonamide moiety (by introducing iso-Pr groups onto the Ph ring) brought about high enantioselectivity in the reaction. Desulfonylation of the diarylmethyl arylsulfonamides yielded chiral diarylmethyl amines, e.g., II.

Angewandte Chemie, International Edition published new progress about Addition reaction catalysts, stereoselective. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Name: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

Referemce:
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

Huang, Yu-Hao; Wu, Yichen; Zhu, Zile; Zheng, Sujuan; Ye, Zihang; Peng, Qian; Wang, Peng published the artcile< Enantioselective Synthesis of Silicon-Stereogenic Monohydrosilanes by Rhodium-Catalyzed Intramolecular Hydrosilylation>, Product Details of C44H40P2, the main research area is enantioselective regioselective preparation stereogenic cyclic monohydrosilane oxasilacycle; rhodium catalyzed intramol hydrosilylation; mol structure calculation cyclic monohydrosilane oxasilacycle; asymmetric synthesis; dihydrosilanes; hydrosilylation; monohydrosilane; rhodium.

Enantiopure monohydrosilanes are versatile chiral reagents for alc. resolution and mechanistic investigation. Herein, authors have demonstrated the asym. synthesis of monohydrosilanes via an intramol. hydrosilylation strategy. This protocol is suitable for the synthesis of five- and six-membered cyclic monohydrosilanes, including a class of chiral oxasilacycles, with excellent diastereo-, regio-, and enantioselectivities. Notably, the catalyst loading could be reduced to 0.1 mol % which makes this one of the most efficient methods to access chiral monohydrosilanes. Mechanistic studies and DFT calculations indicate this Rh-catalyzed intramol. asym. hydrosilylation reaction might proceed via a Chalk-Harrod mechanism, and the enantio-determining step was predicted to be oxidative addition of Si-H bond.

Angewandte Chemie, International Edition published new progress about Crystal structure. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Product Details of C44H40P2.

Referemce:
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

Zhang, Xiaoyong; Mashima, Kazushi; Koyano, Kinko; Sayo, Noboru; Kumobayashi, Hidenori; Akutagawa, Susumu; Takaya, Hidemasa published the artcile< Synthesis of partially hydrogenated 2,2'-bis(diphenylphosphenyl)-1,1'-binaphthyl (BINAP) ligands and their application to catalytic asymmetric hydrogenation>, Safety of (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is bisphosphine chiral partially hydrogenated synthesis ligand; ruthenium catalyst hydrogenation chiral phosphine ligand; asym hydrogenation ruthenium catalyst chiral phosphine; crystal structure chiral diphosphine ruthenium cation; mol structure chiral diphosphine ruthenium cation.

Three pairs of new axially dissym. bisphosphine ligands, (R)-(-)- and (S)-(+)-2,2′-bis(dicyclohexylphosphinyl)-1,1′-binaphthyl [ I, R = C6H11], (R)-(+)- and (S)-(-)-2,2′-bis(diphenylphosphinyl)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl [II, R = Ph], and (R)-(-)- and (S)-(+)-2,2′-bis(dicyclohexylphosphinyl)-5,5′,6,6,7,7′,8,8′-octahydro-1,1′-binaphthyl [II, R = C6H11], have been synthesized. The absolute configurations of the isomers I were determined by single-crystal x-ray diffraction of the linear 1:1 polymeric complex of (S)-(+)-2,2′-bis(dicyclohexylphosphinoyl)-1,1′-binaphthyl [III] and (2R,3R)-(-)-di-O-benzoyltartaric acid [(-)-DBT], and those of the isomers II were established on the basis of CD spectra of the phosphanes and their bisoxides. X-ray crystallog. studies of two cationic Rh1 complexes, [Rh{(S)-Cy-binap}(COD)]ClO4 [(S)-IV] and [Rh{(S)-H8-binap}(COD)]ClO4[(S)-V], revealed that complex (S)-IV possesses a disym. structure, while complex (S)-V has a pseudo-C2-symmetry and shows a significantly large dihedral angle between the two Ph rings [80.3(4)°]. The potentially of ligand II for asym. catalysis was demonstrated in RuII-catalyzed stereoselective hydrogenations of Me 2-(benzamidomethyl)-3-oxobutanoate, (in up to 92% d.e. and 99% e.e.) and geraniol (in 98% optical purity).

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about Crystal structure. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Safety of (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

Referemce:
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

Tanaka, Ken; Fukawa, Naohiro; Suda, Takeshi; Noguchi, Keiichi published the artcile< One-Step Construction of Five Successive Rings by Rhodium-Catalyzed Intermolecular Double [2+2+2] Cycloaddition: Enantioenriched [9]Helicene-Like Molecules>, COA of Formula: C44H40P2, the main research area is tetrayne diyne intermol cycloaddition rhodium catalyst; helicene asym preparation crystal mol structure.

The synthesis of [9]helicene-like mols. by rhodium-catalyzed intermol. double [2+2+2] cycloadditions is presented. Crystal structure and photophys. data for the compounds are also determined

Angewandte Chemie, International Edition published new progress about Alkadiynes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, COA of Formula: C44H40P2.

Referemce:
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

Suda, Takeshi; Noguchi, Keiichi; Tanaka, Ken published the artcile< Rhodium-Catalyzed Asymmetric Formal Olefination or Cycloaddition: 1,3-Dicarbonyl Compounds Reacting with 1,6-Diynes or 1,6-Enynes>, Product Details of C44H40P2, the main research area is dicarbonyl stereoselective olefination diyne enyne rhodium BINAP segphos catalyst.

The Rh(I)/(R)-H8-BINAP complex was used as the catalyst in the asym. intermol. olefination of enolizable 1,3-dicarbonyl compounds with 1,6-diynes by [2+2+2]cycloaddition followed by electrocyclic ring opening. The same reaction was also accomplished with 1,6-enynes by using Rh(I)/S-segphos as catalyst.

Angewandte Chemie, International Edition published new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Product Details of C44H40P2.

Referemce:
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

Tanaka, Rie; Noguchi, Keiichi; Tanaka, Ken published the artcile< Rhodium-catalyzed asymmetric reductive cyclization of heteroatom-linked 5-alkynals with heteroatom-substituted acetaldehydes>, Related Products of 139139-86-9, the main research area is heteroatom alkynal acetaldehyde rhodium catalyst asym reductive cyclization.

We have established that a cationic rhodium(I)/H8-BINAP complex catalyzes the asym. reductive cyclization of heteroatom-linked 5-alkynals with heteroatom-substituted acetaldehydes in good yields with outstanding enantioselectivity.

Journal of the American Chemical Society published new progress about Alkynals Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Related Products of 139139-86-9.

Referemce:
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

Li, Min; Li, Bin; Xia, Hong-Feng; Ye, Danru; Wu, Jing; Shi, Yifeng published the artcile< Mesoporous silica KIT-6 supported superparamagnetic CuFe2O4 nanoparticles for catalytic asymmetric hydrosilylation of ketones in air>, Product Details of C44H40P2, the main research area is silica copper iron oxide nanoparticle catalyst ketone asym hydrosilylation.

A diverse range of prochiral ketones were reduced in air with high yields and good-to-excellent enantioselectivities (up to 97% ee) in the presence of a heterogeneous catalyst system, which was in situ formed from catalytic amounts of superparamagnetic CuFe2O4 nanoparticles supported on mesoporous silica KIT-6 and non-racemic dipyridylphosphine ligand, the stoichiometric hydride donor polymethylhydrosiloxane (PMHS) as well as certain amounts of additives. The magnetically separable catalysts could be efficiently reused 4 times without apparent loss of both the activity and enantioselectivity.

Green Chemistry published new progress about Catalyst supports. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Product Details of C44H40P2.

Referemce:
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

Goulioukina, Nataliya S.; Shergold, Ilya A.; Rybakov, Victor B.; Beletskaya, Irina P. published the artcile< One-Pot Two-Step Synthesis of Optically Active α-Amino Phosphonates by Palladium-Catalyzed Hydrogenation/Hydrogenolysis of α-Hydrazono Phosphonates>, Category: chiral-phosphine-ligands, the main research area is chiral hydrazono amino phosphonate palladium catalyzed enantioselective hydrogenation; crystal structure chiral hydrazono amino phosphonate; mol structure chiral hydrazono amino phosphonate; amino phosphonate chiral preparation optical activity.

An efficient and convenient 1-pot procedure for the stereoselective catalytic synthesis of ring-substituted [amino(phenyl)methyl]phosphonates was developed. The enantioselective hydrogenation of easily available diisopropyl (Z)-[aryl(phenylhydrazono)methyl]phosphonates using Pd(II) acetate as a precatalyst, (R)-2,2′-bis(diphenylphosphino)-5,5′-dichloro-6,6′-dimethoxy-1,1′-biphenyl [(R)-Cl-MeO-BIPHEP] as a ligand, and (1S)-(+)-10-camphorsulfonic acid as an activator in a mixture of 2,2,2-trifluoroethanol and CH2Cl2 at ambient temperature gave corresponding [aryl(2-phenylhydrazino)methyl]phosphonates. The subsequent cleavage of the N-N bond was accomplished with H2 after the addition of Pd on C and MeOH into crude reaction mixture to afford the optically active [amino(aryl)methyl]phosphonates. The method is operationally simple and provides an appreciable enantioselectivity up to 98% ee.

Advanced Synthesis & Catalysis published new progress about Crystal structure. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Category: chiral-phosphine-ligands.

Referemce:
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