Tag: M.W=600-700

Yoshida, Mariko; Nemoto, Tetsuhiro; Zhao, Zengduo; Ishige, Yuta; Hamada, Yasumasa published the artcile< Enantioselective construction of all-carbon quaternary spirocenters through a Pd-catalyzed asymmetric intramolecular ipso-Friedel-Crafts allylic alkylation of phenols>, Computed Properties of 325168-88-5, the main research area is spirocyclohexadienone enantioselective synthesis; phenol Friedel Crafts allylic alkylation chiral ligand Pd catalyst.

A novel catalytic asym. synthetic method for making spirocyclohexadienones e. g., I with an all-carbon quaternary spirocenter was developed based on the Pd-catalyzed intramol. ipso-Friedel-Crafts allylic alkylation of phenols. When 5 mol % of the Pd catalyst and 12 mol % of (-)-9-NapBN (-) were used, the spirocyclic adduct was obtained with up to 93% ee, albeit with low chem. yield. On the other hand, when using 6 mol% of the Trost ligand (R,R), the spirocyclic adducts were obtained in good yields with up to 89% ee (diastereoselectivity = 9.2:1).

Tetrahedron: Asymmetry published new progress about Allylic alkylation. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Computed Properties 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

Araki, Tatsuya; Hojo, Daiki; Noguchi, Keiichi; Tanaka, Ken published the artcile< Enantioselective synthesis of planar chiral paracyclophanes with short ansa chains and structure of strained dioxa[7]paracyclophane>, Recommanded Product: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is paracyclophane planar chiral stereoselective preparation.

The enantioselective synthesis of planar chiral [7] and [8]paracyclophanes has been achieved by the cationic rhodium(I)-(S)-H8-BINAP complex catalyzed [2+2+2] cycloaddition Planar chiral [9]paracyclophanes were also synthesized by the same method. The X-ray crystallog. anal. of the strained dioxa[7]paracyclophane revealed the significant deformation of the benzene ring from planarity.

Synlett published new progress about Enantioselective synthesis. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Recommanded Product: (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

Desfeux, Camille; Besnard, Celine; Mazet, Clement published the artcile< [n]Dendralenes as a Platform for Selective Catalysis: Ligand-Controlled Cu-Catalyzed Chemo-, Regio-, and Enantioselective Borylations>, Recommanded Product: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is phosphanamine copper catalyzed antiMarkovnikov enantioselective borylation substituted dendralene; dendralene preparation enantioselective borylation; crystal structure benzoyl dendralene derivative; mol structure benzoyl dendralene derivative.

The authors report the development of two complementary methods for the Cu-catalyzed anti-Markovnikov borylation of one specific olefin in 2-substituted [n]dendralenes (n = 3-6). The 1st protocol operates with a bisphosphine ligand and occurs with high regio- and chemoselectivity for the terminal double bond, independently of the number of cross-conjugated alkenes. The use of a chiral phosphanamine ligand enables the highly chemo-, regio-, and enantioselective borylation of the alkene cross-conjugated with the terminal olefin in [n]dendralenes.

Organic Letters published new progress about Borylation (anti-Markovnikov enantioselective). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Recommanded Product: (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

Oonishi, Yoshihiro; Saito, Akira; Sato, Yoshihiro published the artcile< Rhodium(I)-Catalyzed Intermolecular [2+2+2] Cycloaddition of Allenyl Aldehydes with Alkynes and Related Cyclization>, SDS of cas: 139139-86-9, the main research area is polysubstituted dihydropyran enantioselective preparation; internal alkyne allenyl aldehyde rhodium catalyst regioselective cycloaddition; dienyl ketone preparation; terminal alkyne allenyl aldehyde rhodium catalyst cycloaddition.

Rhodium(I)-catalyzed cyclization of allenyl aldehydes with various alkynes was investigated. The intermol. [2+2+2] cycloaddition reaction of allenyl aldehyde with internal alkynes that have both an electron-rich aromatic ring and an electron-withdrawing group at the terminus afforded polysubstituted dihydropyran for e.g., I in good yields with good to high regio- and enantioselectivity. While the reactions of terminal alkynes with allenyl aldehyde gave dienyl ketones instead of [2+2+2] cycloaddition products for e.g., II in good yields.

Asian Journal of Organic Chemistry published new progress about Alkadienones 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, SDS of cas: 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

Oonishi, Yoshihiro; Masusaki, Shuichi; Sakamoto, Shunki; Sato, Yoshihiro published the artcile< Rhodium(I)-Catalyzed Enantioselective Cyclization of Enynes by Intramolecular Cleavage of the Rh-C Bond by a Tethered Hydroxy Group>, Reference of 139139-93-8, the main research area is acyl heterocyclic compound enantioselective preparation; enynol preparation enantioselective cyclization rhodium catalyst; cyclization; enantioselectivity; enyne; rhodium; σ-bond metathesis.

Rhodium(I)-catalyzed enantioselective intramol. cyclization of enynes having a hydroxy group in the tether was investigated, and various cyclic compounds possessing a chiral quaternary carbon center were obtained in high yields with high ees. In this cyclization, a Rh-C(sp2) bond in the rhodacyclopentene intermediate, which was formed by enantioselective oxidative cycloaddition of enynes to a chiral rhodium(I) complex, was intramolecularly cleaved by σ-bond metathesis of a tethered O-H bond in the substrate. Furthermore, it was found that the cyclic compounds were obtained with high ees even when the starting materials having a racemic secondary alc. moiety were used in this reaction.

Angewandte Chemie, International Edition published new progress about Alcohols, unsaturated Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Reference 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

Yasuda, Shigeo; Kawaguchi, Yasuaki; Okamoto, Yuta; Mukai, Chisato published the artcile< Chemo- and Regioselective Rhodium(I)-Catalyzed [2+2+2] Cycloaddition of Allenynes with Alkynes>, SDS of cas: 139139-93-8, the main research area is allenyne alkyne rhodium cycloaddition catalyst; benzene fused bicyclic preparation; alkynes; allenes; cycloaddition; regioselectivity; rhodium.

A highly chemo- and regioselective partially intramol. rhodium(I)-catalyzed [2+2+2] cycloaddition of allenynes with alkynes is described. A range of diverse polysubstituted benzene derivatives could be synthesized in good to excellent yields, in which the allenynes served as synthetic equivalent to the diynes. A high regioselectivity could be observed when allenynes were treated with unsym. alkynes.

Chemistry – A European Journal published new progress about [2+2+2] Cycloaddition reaction. 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

Duan, Ying; Chen, Mu-Wang; Ye, Zhi-Shi; Wang, Duo-Sheng; Chen, Qing-An; Zhou, Yong-Gui published the artcile< An enantioselective approach to 2,3-disubstituted indolines through consecutive Bronsted Acid/Pd-complex-promoted tandem reactions>, Name: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is indoline chiral preparation tandem condensation asym hydrogenation indole aldehyde; hydrogenation catalyst asym palladium BINAP SynPhos complex indoline preparation; indole alkylation reductive tandem preparation chiral indoline.

Chiral substituted indolines, R1-2-R2-3-CH2R3-2,3-dihydro-1H-indoles (3, R1 = H, 5-F, 7-Me; R2 = Me, Bu, CH2CH2Ph; R3 = Ph, 4-MeOC6H4, 4-FC6H4, cyclohexyl, iPr) were prepared by tandem aldol addition-asym. hydrogenation reaction of R1-2-R2-1H-indoles with aldehydes R3CHO, catalyzed by TsOH and Pd-BINAP complexes. The reaction mechanism comprises Bronsted acid-catalyzed condensation and formation of 3-alkylideneiminium intermediate, which is then hydrogenated by in situ formed palladium diphosphine complexes, the (R)-H8-BINAP and (R)-SynPhos [2,2′,3,3′-tetrahydro[5,5′-bi-1,4-benzodioxin]-6,6′-bis(diphenylphosphine)] being the most effective ligands.

Chemistry – A European Journal published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 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

Yasui, Takeshi; Nakazato, Yuya; Kurisaki, Koutarou; Yamamoto, Yoshihiko published the artcile< Enantioselective Construction of 5-6-5 Tricyclic Lactone Framework Bearing a Quaternary Bridgehead Carbon via Rh-Catalyzed Asymmetric [2+2+2] Cycloaddition of Enediynes>, Name: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is tricyclic cyclohexadiene lactone preparation enantioselective; enediyne cycloaddition rhodium catalyst.

Herein, a Rh-catalyzed asym. [2+2+2] cycloaddition of ene-yne-yne enediynes to generate enantio-enriched tricyclic cyclohexadienes bearing a quaternary bridgehead carbon is reported. The Rh-Phanephos complex is an appropriate catalyst for the cycloaddition of enediynes bearing an unsubstituted propiolate terminus, whereas Rh-biaryl bisphosphine catalysts, which have been widely used for asym. cycloadditions of alkynes and alkenes, are not applicable for the reaction of such enediynes. Several control experiments suggest that the reaction using the Rh-Phanephos complex exclusively proceeds via a rhodacyclopentadiene intermediate, unlike when using a Rh-biaryl bisphosphine complex that can form a rhodacyclopentadiene intermediate as well as a rhodacyclopentene intermediate in a substrate-dependent manner.

Advanced Synthesis & Catalysis published new progress about [2+2+2] Cycloaddition reaction (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

Zhang, Xiaoyong; Mashima, Kazushi; Koyano, Kinko; Sayo, Noboru; Kumobayashi, Hidenori; Akutagawa, Susumu; Takaya, Hidemasa published the artcile< Synthesis of partially hydrogenated BINAP variants>, Application of C44H40P2, 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 139139-86-9. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Application 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

Augustine, Robert; Tanielyan, Setrak; Marin, Norman; Alvez, Gabriela published the artcile< Synthesis of chiral 2-amino-1-phenylethanol>, Application of C48H50P2, the main research area is aminophenylethanol stereoselective preparation phenacyl chloride.

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

Chemical Industries (Boca Raton, FL, United States) published new progress about Chiral ligands Role: CAT (Catalyst Use), USES (Uses). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Application of C48H50P2.

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