Day: October 13, 2022

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

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

Franckevicius, Vilius; Cuthbertson, James D.; Pickworth, Mark; Pugh, David S.; Taylor, Richard J. K. published the artcile< Asymmetric Decarboxylative Allylation of Oxindoles>, Computed Properties of 152140-65-3, the main research area is stereoselective palladium catalyzed decarboxylative allylation oxindole allyl ester; oxindole allyl derivative stereoselective preparation; stereoselectivity reversal substituent size facial selectivity allylation.

An asym. decarboxylative palladium-catalyzed allylation of alkyl- and aryl-substituted oxindoles has been developed, enabling the installation of an all-carbon quaternary chiral center at the oxindole 3-position in excellent yields and good to excellent enantioselectivity. An intriguing substrate-dependent reversal in stereoselectivity has been observed, whereby the size of the substituent determines the facial selectivity in the allylation step.

Organic Letters published new progress about Allylation catalysts, stereoselective (decarboxylative). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Computed Properties of 152140-65-3.

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

Lipshutz, Bruce H.; Servesko, Jeff M. published the artcile< CuH-catalyzed asymmetric conjugate reductions of acyclic enones>, SDS of cas: 277306-29-3, the main research area is enone conjugate copper catalyzed stereoselective reduction; alkanone asym synthesis.

A CuH-catalyzed asym. conjugate reduction of acyclic enones is reported. The reduction of enones was carried out with a catalytic amount of triphenylphosphine-copper hydride, in the presence of a chiral ligand, to afford alkanones, e.g. I, in high yields and enantiomeric excess.

Angewandte Chemie, International Edition published new progress about Aliphatic ketones Role: SPN (Synthetic Preparation), PREP (Preparation). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, SDS of cas: 277306-29-3.

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

Murayama, Koichi; Shibata, Yu; Sugiyama, Haruki; Uekusa, Hidehiro; Tanaka, Ken published the artcile< Synthesis, structure, and photophysical/chiroptical properties of benzopicene-based π-conjugated molecules>, Electric Literature of 139139-93-8, the main research area is benzopicene pi conjugated hydrocarbon ladder helical structure preparation cycloaddition; cycloaddition dialkynyl binaphthalene preparation benzopicene ladder helical polycycle; crystal structure helical benzopicene fluorenone ketone.

The convenient synthesis of substituted benzopicenes and azabenzopicenes I (X = C, N; R1, R2 = H, CO2Et, alkyl, CH2CH) has been achieved by the cationic rhodium(I)/H8-BINAP or BINAP complex-catalyzed [2+2+2] cycloaddition of 1,1′-dialkynyl-2,2′-binaphthalene under mild conditions. This method was applied to the synthesis of benzopicene-based long ladder (II, R3 = C12H25) and helical (III, R4 = Ph, Bu; Y2 = O, 9-fluorenylidene) mols. The x-ray crystal structure anal. revealed that the benzopicene-based helical mol. is highly distorted and the average distance of overlapped rings is markedly shorter than that in the triphenylene-based helical mol. Photophys. and chiroptical properties of these benzopicene and azabenzopicene derivatives have also been examined With respect to photophys. properties, substituted benzopicenes and azabenzopicenes showed red shifts of absorption and emission maxima compared with the corresponding triphenylenes and azatriphenylenes. With respect to chiroptical properties, the CPL spectra of the benzopicene-based helical mol. showed two opposite peaks, and thus the value of the CPL was smaller than that of the triphenylene-based helical mol. presumably due to the presence of two chiral fluorophores.

Journal of Organic Chemistry published new progress about [2+2+2] Cycloaddition reaction. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature 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

Tanaka, Ken; Shirasaka, Kaori published the artcile< Highly Chemo- and Regioselective Intermolecular Cyclotrimerization of Alkynes Catalyzed by Cationic Rhodium(I)/Modified BINAP Complexes>, Category: chiral-phosphine-ligands, the main research area is chemoselective regioselective intermol cocyclotrimerization alkyne cationic rhodium BINAP complex; diethyl acetylenedicarboxylate chemoselective regioselective intermol cocyclotrimerization rhodium BINAP complex.

Cationic rhodium(I)/modified BINAP complexes are effective catalysts for highly regioselective intermol. cyclotrimerization of terminal alkynes and highly chemo- and regioselective intermol. cocyclotrimerization of di-Et acetylenedicarboxylate (DEAD) and terminal alkynes. It is a noteworthy example of intermol. cocyclotrimerization of two different alkynes in terms of catalytic activity, chemo- and regioselectivity, scope of substrates, and ease of operation. The wide applicability of this new cocyclotrimerization procedure is demonstrated in the one-step synthesis of [6]metacyclophane.

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, 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

Masutomi, Koji; Sugiyama, Haruki; Uekusa, Hidehiro; Shibata, Yu; Tanaka, Ken published the artcile< Asymmetric Synthesis of Protected Cyclohexenylamines and Cyclohexenols by Rhodium-Catalyzed [2+2+2] Cycloaddition>, HPLC of Formula: 139139-86-9, the main research area is protected cyclohexenylamine cyclohexenol preparation rhodium catalyst cycloaddition; asymmetric catalysis; cycloadditions; enamides; reaction mechanisms; rhodium.

Cationic rhodium(I)/axially chiral biaryl bis(phosphine) complexes catalyze the asym. [2+2+2] cycloaddition of 1,6-enynes with electron-rich functionalized alkenes, enamides, and vinyl carboxylates, to produce the corresponding protected cyclohexenylamines and cyclohexenols. Regioselectivity depends on structures of substrates. The present cycloaddition was successfully applied to the enantioselective total synthesis of (-)-porosadienone by using the amide moiety as a leaving group.

Angewandte Chemie, International Edition published new progress about [2+2+2] Cycloaddition reaction. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, HPLC of Formula: 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

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>, Electric Literature of 139139-93-8, 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). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature 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