Day: October 18, 2022

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

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

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

Trost, Barry M.; Czabaniuk, Lara C. published the artcile< Palladium-Catalyzed Asymmetric Benzylation of 3-Aryl Oxindoles>, Safety of N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide], the main research area is aryloxindole enantioselective preparation; aralkyl carbonate aryloxindole asym benzylation palladium catalyst.

Palladium-catalyzed asym. benzylic alkylation with 3-aryl oxindoles as prochiral nucleophiles is reported. Proceeding analogously to asym. allylic alkylation, asym. benzylation occurs in high yield and enantioselectivity for a variety of unprotected 3-aryl oxindoles and benzylic Me carbonates using chiral bisphosphine ligands. This methodol. represents a novel asym. carbon-carbon bond formation between a benzyl group and a prochiral nucleophile to generate a quaternary center, e.g., I.

Journal of the American Chemical Society published new progress about Aryl aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Safety of N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide].

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

Lavernhe, Remi; Alexy, Eric J.; Zhang, Haiming; Stoltz, Brian M. published the artcile< Palladium-Catalyzed Enantioselective Decarboxylative Allylic Alkylation of Protected Benzoin-Derived Enol Carbonates>, SDS of cas: 152140-65-3, the main research area is benzoin preparation enantioselective; allyl enol carbonate preparation decarboxylative allylic alkylation palladium catalyst; allylic alkylation; asymmetric catalysis; benzoin; palladium catalysis.

The enantioselective palladium-catalyzed decarboxylative allylic alkylation of fully substituted α-hydroxy acyclic enol carbonates (Z)-RC(OCO2allyl)=C(OMOM)R (R = C6H5, 2-naphthyl, 2H-1,3-benzodioxol-5-yl, etc.) providing tetrasubstituted benzoin derivatives (S)-RC(O)C(OMOM)(CH2CH=CH2)R is reported. Investigation into the transformation revealed that preparation of the starting material as a single enolate isomer is crucial for optimal enantioselectivity. The obtained alkylation products contain multiple reactive sites that can be utilized toward the synthesis of stereochem. rich derivatives

Advanced Synthesis & Catalysis published new progress about Allylic alkylation catalysts, stereoselective (decarboxylative). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, SDS of cas: 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

Denk, Michael K.; Milutinovic, Nicholas S.; Dereviankin, Mikhail Y. published the artcile< Reduction of halocarbons to hydrocarbons by NADH models and NADH>, Electric Literature of 606-68-8, the main research area is halocarbon reduction bond dissociation energy toxicol; Bond dissociation energy; DDT; Halocarbons; Metabolic disruption; NADH; Toxicology.

The reduction of halocarbons by NADH models and NADH under ambient conditions is reported as a new type of reactivity pointing towards a hitherto unknown disruptive pathway for NADH/NADPH-dependent processes. The reaction was studied with the omnipresent pesticide DDT, the inhalation anesthetic halothane, and several simple halocarbons. The halide-hydride exchange represents a biochem. equivalent for the reduction of halocarbons by traditional synthetic reagents like silanes (R3Si-H) and stannanes (R3Sn-H). High precision thermochem. calculations (CBS-QB3) reveal the carbon-hydrogen bond dissociation energy of NADH (70.8 kcal·mol-1) to be lower than that of stannane (SnH4: 78.1 kcal·mol-1), approaching that of the elusive plumbane (PbH4: 68.9 kcal·mol-1). The ready synthetic accessibility of NADH models, their low carbon-hydrogen bond dissociation energy, and their dehalogenation activity in the presence of air and moisture recommend these compounds as substitutes for the air-sensitive or toxic metal hydrides currently employed in synthesis.

Chemosphere published new progress about C-H bond energy. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Electric Literature of 606-68-8.

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

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

Luo, Mingfang; Xing, Jianmin; Gou, Zhongxuan; Li, Shan; Xie, Yuchun; Liu, Huizhou; Chen, Jiayong published the artcile< Effects of aqueous media on microbial removal of sulfur from dibenzothiophene in the presence of hydrocarbons>, Application of C21H27N7Na2O14P2, the main research area is dibenzothiophene microbial desulfurization bacteria hydrocarbon; biodesulfurization dibenzothiophene bacteria hydrocarbon.

Effects of the aqueous components, pH, concentration of NaCl, and volume ratios of oil-to-water on the desulfurization activity of gram-neg. desulfurizing bacterium, Pseudomonas delafieldii R-8, were investigated. R-8 showed high desulfurization activity even with a concentration of NaCl up to 60 g · L-1 or high content of dodecane over 83%. The addition of NADH could increase the desulfurization activity. The desulfurization of DBT could be proceeded in the presence of hydrocarbons with the carbon length ranging from 6 to 16. Among them, the highest specific desulfurization activity was shown in dodecane, the value of which was 1.96 mg · g-1 · h-1 similar to that of R. erythropolis IGTS8.

Chinese Science Bulletin published new progress about Acidovorax delafieldii. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Application of C21H27N7Na2O14P2.

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

Yoshizaki, Soichi; Nakamura, Yu; Masutomi, Koji; Yoshida, Tomoka; Noguchi, Keiichi; Shibata, Yu; Tanaka, Ken published the artcile< Rhodium-Catalyzed Asymmetric [2 + 2 + 2] Cycloaddition of 1,6-Enynes with Cyclopropylideneacetamides>, Reference of 139139-93-8, the main research area is asym cycloaddition enyne cyclopropylideneacetamide rhodium catalyst.

It has been established that a cationic rhodium(I)/(S)-H8-BINAP complex catalyzes the asym. [2+2+2] cycloaddition of 1,6-enynes with cyclopropylideneacetamides to produce spirocyclohexenes in excellent enantioselectivity with retaining cyclopropane rings. E.g., in presence of [Rh(cod)2]BF4 and (S)-H8-BINAP, [2+2+2] cycloaddition of MeCCCH2NTsCH2CMe:CH2 and N-methyl-N-phenylcyclopropylideneacetamide gave 69% I (>99%ee).

Organic Letters published new progress about [2+2+2] Cycloaddition reaction. 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

Lautens, Mark; Fagnou, Keith; Taylor, Mark published the artcile< Rhodium-catalyzed asymmetric ring opening of oxabicyclic alkenes with phenols>, SDS of cas: 277306-29-3, the main research area is oxabicyclic alkene asym ring opening phenol; rhodium asym ring opening oxabicyclic alkene; stereoselective enantioselective aryloxydihydronaphthalenol preparation.

The scope of the rhodium-catalyzed asym. ring opening reaction of oxabenzonorbornadiene has been extended to include phenolic nucleophiles XC6H4OH (X = 4-F, 4-Cl, 4-Br, 4-I, 4-MeCO, 4-F3C, 4-Me, 4-NC, 2-Br, 3-Br). The enantioenriched, functionalized dihydronaphthalene products, e.g., aryloxydihydronaphthalenol I, are highly valuable intermediates for which no other practical methods of preparation are available. Using [Rh(CO)2Cl]2 as the rhodium source and ferrocene II as the diphosphine ligand allows the use of less reactive o-halophenols in the stereoselective ring opening reaction. The utility of these products has been demonstrated through their application in the synthesis of benzofuran polycyclic materials, e.g, III.

Organic Letters published new progress about Alkenes Role: RCT (Reactant), RACT (Reactant or Reagent). 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