Tag: M.W=600-700

Konrad, Tina M.; Fuentes, Jose A.; Slawin, Alexandra M. Z.; Clarke, Matthew L. published the artcile< Highly Enantioselective Hydroxycarbonylation and Alkoxycarbonylation of Alkenes using Dipalladium Complexes as Precatalysts>, Application In Synthesis of 325168-88-5, the main research area is paracyclophane diphosphine palladium complex preparation enantioselective hydroxycarbonylation alkoxycarbonylation catalyst; styrene norbornene asym hydroxycarbonylation alkoxycarbonylation palladium phanephos catalyst.

A highly stereoselective process for hydroxycarbonylation and alkoxycarbonylation of alkenes [styrene, 4-(tert-butyl)styrene, norbornene] using (R)-PHANEPHOS- and (R)- or (S)-Xylyl-PHANEPHOS-bridged dipalladium complexes as precatalysts has been developed. The process operates below 100 °C, uses less than 1 equivalent of an acid promoter and delivers the product with up to 95% ee.

Angewandte Chemie, International Edition published new progress about Aliphatic acids Role: SPN (Synthetic Preparation), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Application In Synthesis of 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

Wang, Duo-Sheng; Chen, Qing-An; Li, Wei; Yu, Chang-Bin; Zhou, Yong-Gui; Zhang, Xumu published the artcile< Pd-Catalyzed Asymmetric Hydrogenation of Unprotected Indoles Activated by Bronsted Acids>, Formula: C44H40P2, the main research area is indoline asym preparation reaction mechanism; unprotected indole asym hydrogenation palladium catalyst Bronsted acid activator; dynamic kinetic resolution.

The first highly enantioselective hydrogenation of simple indoles was developed with a Bronsted acid as an activator to form the iminium intermediate in situ, which was hydrogenated using Pd(OCOCF3)2/(R)-H8-BINAP catalyst system with up to 96% ee. The present method provides an efficient route to enantioenriched 2-substituted, e.g., I and 2,3-disubstituted indolines.

Journal of the American Chemical Society published new progress about Bronsted acids Role: CAT (Catalyst Use), USES (Uses). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, 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

Hatano, Manabu; Terada, Masahiro; Mikami, Koichi published the artcile< Highly enantioselective palladium-catalyzed ene-type cyclization of a 1,6-enyne>, Quality Control of 139139-93-8, the main research area is furan vinyl methoxycarbonylmethylidene methyl preparation enantioselective; palladium catalyzed carbocyclization enyne; crystal structure vinylmethylcaboxymethylidenefuran phenylethylamine salt; asymmetric catalysis; cyclizations; enynes; palladium.

The authors developed a highly efficient palladium(II)-catalyzed ene-type carbocyclization of 1,6-enyne MeCH=C(Me)CH2OCH2CCCO2Me leading to enantiopure furan (I). This highly enantioselective catalysis is applicable for the construction of an enantioenriched quaternary chiral center. Possible mechanisms including neutral and cationic intermediate have been proposed.

Angewandte Chemie, International Edition published new progress about Alkenynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Quality Control of 139139-93-8.

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

Sagae, Hiromi; Noguchi, Keiichi; Hirano, Masao; Tanaka, Ken published the artcile< Rhodium-catalyzed enantio- and diastereoselective intramolecular [2 + 2 + 2] cycloaddition of unsymmetrical dienynes>, Name: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is dienyne rhodium catalyst intramol cycloaddition; polycyclic cyclohexene derivative stereoselective preparation crystal structure; benzopyran derivative stereoselective preparation; biscyclooctadienerhodium tetrafluoroborate octahydrobinap asym cycloaddition catalyst.

A cationic rhodium(I)/(R)-H8-BINAP or (R)-Segphos complex catalyzes an intramol. [2 + 2 + 2] cycloaddition of unsym. dienynes, leading to fused tri- and tetracyclic cyclohexenes bearing two tertiary or quaternary carbon centers in high yields with high enantio- and diastereoselectivity.

Chemical Communications (Cambridge, United Kingdom) published new progress about Alkenynes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) (dienynes). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Name: (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; Nishida, Goushi; Ogino, Masakazu; Hirano, Masao; Noguchi, Keiichi published the artcile< Enantioselective synthesis of axially chiral biaryls through rhodium-catalyzed complete intermolecular cross-cyclotrimerization of internal alkynes>, Product Details of C44H40P2, the main research area is alkyne acetylenedicarboxylate cross cyclotrimerization rhodium BINAP; biaryl asym preparation; benzenetetracarboxylate preparation.

A cationic rhodium(I)/H8-BINAP complex-catalyzed complete intermol. cross-cyclotrimerization of internal alkynes with dialkyl acetylenedicarboxylates was developed. This reaction was successfully applied to enantioselective synthesis of axially chiral biaryls, e.g., I, utilizing internal alkynes bearing ortho-substituted Ph and acetoxymethyl in each terminal position. The axial chirality was constructed at the formation of benzene rings with high enantioselectivity.

Organic Letters published new progress about Alkynes 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

Nogami, Juntaro; Tanaka, Yusuke; Sugiyama, Haruki; Uekusa, Hidehiro; Muranaka, Atsuya; Uchiyama, Masanobu; Tanaka, Ken published the artcile< Enantioselective Synthesis of Planar Chiral Zigzag-Type Cyclophenylene Belts by Rhodium-Catalyzed Alkyne Cyclotrimerization>, Quality Control of 139139-93-8, the main research area is zigzag cyclophenylene belt enantioselective preparation; rhodium catalyst enantioselective cyclotrimerization heptynyl oxypropynylphenoxyphenylene oligomer; mol crystal structure racemic zigzag cyclophenylene belt; mechanism enantioselectivity cyclotrimerization heptynyl oxypropynylphenoxyphenylene; ring strain calculated zigzag cyclophenylene belt; fluorescence UV visible absorption zigzag cyclophenylene belt; dissymetry factor ECD CPL nonracemic zigzag cyclophenylene belt.

Planar chiral zigzag-type [8] and [12]cyclophenylene belts were prepared enantioselectively by rhodium-catalyzed enantioselective intramol. sequential cyclotrimerizations of a cyclic [oxypropynylbis(heptynyloxy)phenoxybis(heptynyl)phenylene] dimer and trimer. The observed enantioselectivity likely arose from the regioselective formation of a rhodacyclic intermediate from an unsym. triyne unit. The structure of the racemic zigzag [8]cyclophenylene belt was determined by X-ray crystallog.; the homochiral belts mesh with one another to form columns in the solid state, with columns of alternating chiralities. The ring strain of the zigzag [8]cyclophenylene belt was smaller than that of the corresponding armchair-type cycloparaphenylene despite its smaller ring size because of the presence of strain-relieving m-terphenyl moieties. The effect of the number of the benzene rings in the zigzag cyclophenylene belts on their UV/visible absorption and fluorescence was small because of the interruption of conjugation by the m-phenylene moieties, but the effect of bending on the absorption and emission peaks and on the absolute fluorescence quantum yield was significant. Modest anisotropy dissymmetry factors of the electronic CD and CPL spectra were observed for the zigzag [8]cyclophenylene belt.

Journal of the American Chemical Society published new progress about Circular dichroism (electronic). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Quality Control of 139139-93-8.

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

Shen, Zengming; Lu, Xiyan; Lei, Aiwen published the artcile< Highly enantioselective hydrogenation of exocyclic double bond of N-tosyloxazolidinones catalyzed by a neutral rhodium complex and its synthetic applications>, Related Products of 139139-93-8, the main research area is alkylideneoxazolidinone stereoselective hydrogenation rhodium catalyst.

A highly enantioselective synthesis of optically active N-tosyl-4-alkyl-1,3-oxazolidin-2-ones based on the asym. hydrogenation of the trisubstituted exocyclic double bond of N-tosyl-4-alkylidene-1,3-oxazolidin-2-ones under the catalysis of neutral [Rh(COD)Cl]2 and (S)-(+)-DTBM-SEGPHOS was developed. The utility of this highly enantioselective reaction was exemplified by the synthesis of optically active amino acids, amino alcs., and piperidine derivatives

Tetrahedron published new progress about Amino acids Role: SPN (Synthetic Preparation), PREP (Preparation). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Related Products of 139139-93-8.

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

Yang, Bo; Yang, Wu; Guo, Yonghong; You, Lijun; He, Chuan published the artcile< Enantioselective Silylation of Aliphatic C-H Bonds for the Synthesis of Silicon-Stereogenic Dihydrobenzosiloles>, Reference of 139139-86-9, the main research area is rhodium catalyzed enantioselective silylation cyclization styrene derivative arylsilane; silicon stereogenic dihydrobenzosilole containing dehydrocholesterol preparation crystal structure; mol structure silicon stereogenic dihydrobenzosilole containing dehydrocholesterol; C(sp3)−H silylation; asymmetric catalysis; dihydrobenzosiloles; hydrosilylation; silanes.

A Rh(I)-catalyzed enantioselective silylation of aliphatic C-H bonds for the synthesis of Si-stereogenic dihydrobenzosiloles is demonstrated. This reaction involves a highly enantioselective intramol. C(sp3)-H silylation of dihydrosilanes, followed by a stereospecific intermol. alkene hydrosilylation leading to the asym. tetrasubstituted silanes. A wide range of dihydrosilanes and alkenes displaying various functional groups are compatible with this process, giving access to a variety of highly functionalized Si-stereogenic dihydrobenzosiloles in good to excellent yields and enantioselectivities.

Angewandte Chemie, International Edition published new progress about Crystal structure. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Reference 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

Zhang, Xiaoyong; Mashima, Kazushi; Koyano, Kinko; Sayo, Noboru; Kumobayashi, Hidenori; Akutagawa, Susumu; Takaya, Hidemasa published the artcile< Synthesis of partially hydrogenated BINAP variants>, SDS of cas: 139139-93-8, the main research area is BINAP hydrogenated; crystal structure cyclohexylphosphinylbinaphthyl; mol structure cyclohexylphosphinylbinaphthyl; binaphthyl hydro atropisomeric phosphine ligand.

Three pairs of new axially dissym. diphosphine ligands, (R)-(-)- and (S)-(+)-2,2′-bis(dicyclohexylphosphino)-1,1′-binaphthyl, (R)-(+)- and (S)-(-)-2,2′-bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl and (R)-(-)- and (S)-(+)-2,2′-bis(dicyclohexylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, have been synthesized and their absolute configurations have been determined on the basis of an x-ray anal. and CD spectra.

Tetrahedron Letters published new progress about 139139-93-8. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, SDS of cas: 139139-93-8.

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

Nguyen, Qui-Hien; Guo, Shu-Min; Royal, Titouan; Baudoin, Olivier; Cramer, Nicolai published the artcile< Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C-H Arylation of Heteroarenes>, Formula: C44H40P2, the main research area is heteroarene azole palladium monooxidized bisphosphine chiral ligand enantioselective arylation; atropisomeric heterobiaryls preparation.

Atropisomeric (hetero)biaryls are motifs with increasing significance in ligands, natural products, and biol. active mols. The straightforward construction of the stereogenic axis by efficient C-H functionalization methods is extremely rare and challenging. An intermol. and highly enantioselective C-H arylation of relevant heteroarenes providing an efficient access to atropisomeric (hetero)biaryls is reported. The use of a Pd(0) complex equipped with H8-BINAPO as a chiral ligand enables the direct functionalization of a broad range of 1,2,3-triazoles and pyrazoles in excellent yields and selectivities of up to 97.5:2.5 er. The method also allows for an atroposelective double C-H arylation for the construction of two stereogenic axes with >99.5:0.5 er.

Journal of the American Chemical Society published new progress about Arylation catalysts, stereoselective. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, 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