134236-28-5Relevant academic research and scientific papers
Development of a hemilabile P-P=O ligand based on the concept of conformational control
Suzuki, Kiyoto,Ishii, Satoru,Kondo, Kazuhiro,Aoyama, Toyohiko
, p. 648 - 650 (2006)
Development of a new hemilabile P-P=O ligand based on the concept of conformational control is described. In Rh-catalyzed enantioselective phenylation of aromatic aldehydes with phenylboronic acid, MOD-DIOP monophosphine oxide is shown to function as a good ligand. Georg Thieme Verlag Stuttgart.
Binaphthyl-prolinol chiral ligands: Design and their application in enantioselective arylation of aromatic aldehydes
Yao, Chao,Chen, Yaoqi,Sun, Ruize,Wang, Chao,Huang, Yue,Li, Lin,Li, Yue-Ming
supporting information, p. 3644 - 3655 (2021/05/04)
Binaphthyl-prolinol ligands were designed and applied in enantioselective arylation of aromatic aldehydes and sequential arylation-lactonization of methyl 2-formylbenzoate. Under optimized conditions, the reactions provided the desired diarylmethanols and 3-aryl phthalides in up to 96% yields with up to 99% ee and up to 89% yields with up to 99% ee, respectively. In particular, essentially optically pure 3-aryl phthalides (over 99% ee) were obtained in large quantities through recrystallization. This journal is
Enantioselective α-Arylation of Primary Alcohols under Sequential One-Pot Catalysis
Aleksandrova, Maiia,Dydio, Pawe?,Lainer, Bruno,Lichosyt, Dawid
, p. 9253 - 9262 (2021/06/30)
Secondary benzylic alcohols and diarylmethanols are common structural motifs of biologically active and medicinally relevant compounds. Here we report their enantioselective synthesis by α-arylation of primary aliphatic and benzylic alcohols under sequential catalysis integrating a Ru-catalyzed hydrogen transfer oxidation and a Ru-catalyzed nucleophilic addition. The method can be applied to various alcohols and aryl nucleophiles tolerating a range of functional groups, including secondary alcohols, ketones, alkenes, esters, NH amides, tertiary amines, aryl halides, and heterocycles.
Molecular switch manipulating Prelog priority of an alcohol dehydrogenase toward bulky-bulky ketones
Xu, Guochao,Dai, Wei,Wang, Yue,Zhang, Lu,Sun, Zewen,Zhou, Jieyu,Ni, Ye
, (2019/12/27)
Structure-guided rational design revealed the molecular switch manipulating the Prelog and anti-Prelog priorities of an NADPH-dependent alcohol dehydrogenase toward prochiral ketones with bulky and similar substituents. Synergistic effects of unconserved residues at 214 and 237 in small and large substrate binding pockets were proven to be vital in governing the stereoselectivity. The ee values of E214Y/S237A and E214C/S237 G toward (4-chlorophenyl)-(pyridin-2-yl)-methanone were 99.3% (R) and 78.8% (S) respectively. Substrate specificity analysis revealed that similar patterns were also found with (4’-chlorophenyl)-phenylmethanone, (4’-bromophenyl)-phenylmethanone and (4’-nitrophenyl)-phenylmethanone. This study provides valuable evidence for understanding the molecular mechanism on enantioselective recognition of prochiral ketones by alcohol dehydrogenase.
Isosterically designed chiral catalysts: Rationale, optimization and their application in enantioselective nucleophilic addition to aldehydes
Gao, En,Li, Qiao,Duan, Lili,Li, Lin,Li, Yue-Ming
supporting information, (2020/10/20)
Proline-based N,N′-dioxide ligands were designed on the basis of isosteric approach, and were successfully applied in enantioselective nucleophilic addition to aldehydes. In the presence of 10 mol% of chiral ligand 1b, enantioselective addition of diethylzinc to aldehydes provided the corresponding secondary alcohols in up to 90% isolated yield and up to 99% ee. Similarly, using 3e as chiral ligand, enantioselective arylation and alkynylation of aldehydes also proceeded readily, leading to the desired chiral alcohols in up to 92% isolated yield at 99% ee and 80% isolated yields and up to 84% ee, respectively. The current work would shed light on expanding the structure diversity in the design of chiral ligands and chiral catalysts.
Enantioselective Diarylcarbene Insertion into Si-H Bonds Induced by Electronic Properties of the Carbenes
Evans, Declan,Houk, K. N.,Li, Mao-Lin,Li, Wen-Tao,Xu, Bin,Yang, Liang-Liang,Zhou, Qi-Lin,Zhu, Shou-Fei
, p. 12394 - 12399 (2020/08/06)
Catalytic enantioselection usually depends on differences in steric interactions between prochiral substrates and a chiral catalyst. We have discovered a carbene Si-H insertion in which the enantioselectivity depends primarily on the electronic characteristics of the carbene substrate, and the log(er) values are linearly related to Hammett parameters. A new class of chiral tetraphosphate dirhodium catalysts was developed; it shows excellent activity and enantioselectivity for the insertion of diarylcarbenes into the Si-H bond of silanes. Computational and mechanistic studies show how the electronic differences between the two aryls of the carbene lead to differences in energies of the diastereomeric transition states. This study provides a new strategy for asymmetric catalysis exploiting the electronic properties of the substrates.
Water soluble Ru (II)–p-cymene complexes of chiral aroylthiourea ligands derived from unprotected D/L-alanine as proficient catalysts for asymmetric transfer hydrogenation of ketones
Sheeba, Mani Mary,Tamizh, Manoharan Muthu,Bhuvanesh, Nattamai S.P.,Karvembu, Ramasamy
, (2019/01/04)
The newfangled chiral aroylthiourea ligands (L1-L6) were produced from unprotected D/L-alanine and their water soluble Ru (II) organometallic catalysts (1–6) were designed from their reaction with [RuCl2(η6-p-cymene)]2. The analytical and spectral methods were used to confirm the structure of the ligands and complexes. The solid state structure of L1, 5 and 6 was confirmed by single crystal XRD. The organometallic compounds (1–6) catalyzed the asymmetric transfer hydrogenation of aromatic, heteroaromatic and bulky ketones to yield respective enantiopure secondary alcohols with admirable conversions (up to 99%) and attractive enantiomeric excesses (ee up to 98%), in presence of formic acid and triethylamine in water medium under non-inert atmospheric conditions.
Synthesis and electrochemical characterization of iminophosphine-based ruthenium(II) complexes and application in asymmetric transfer hydrogenation reaction as catalysts
Kele?, Mustafa,Kele?, Hülya,Y?lmaz, Mustafa Kemal
, p. 945 - 951 (2019/04/10)
A range of Ru(II) complexes have been prepared with chiral iminophosphine ligands ([(2-PPh2)C6H4CH=NCH(CH3)C6H5(4-R)]; R = –H, p-CH3, p-NO2) and characterized by 1H, 13C, 31P{1H} NMR and FTIR spectroscopy. The electrochemical properties of the [Ru(PN)2Cl2] complexes were investigated in ACN/TBAP solution with cyclic voltammetry and square wave voltammetry techniques. The use of chiral [Ru(PN)2Cl2] complexes as catalysts for the asymmetric transfer hydrogenation of aromatic and aliphatic ketones was studied in 2-propanol in an attempt to demonstrate the effect of substituents, which attached to the phenyl ring bonded to the nitrogen donor, on the catalytic activity and enantioselectivity. It was seen that the electronic effects of these substituents did not contribute to the catalytic efficiency of the ruthenium(II) catalysts.
Combined Photoredox/Enzymatic C?H Benzylic Hydroxylations
Betori, Rick C.,May, Catherine M.,Scheidt, Karl A.
supporting information, p. 16490 - 16494 (2019/11/03)
Chemical transformations that install heteroatoms into C?H bonds are of significant interest because they streamline the construction of value-added small molecules. Direct C?H oxyfunctionalization, or the one step conversion of a C?H bond to a C?O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single-flask photoredox/enzymatic process for direct C?H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity. This unified strategy advances general photoredox and enzymatic catalysis synergy and enables chemoenzymatic processes for powerful and selective oxidative transformations.
Enantiopure Methyl- A nd Phenyllithium: Mixed (Carb-)Anionic Anisyl Fencholate-Aggregates
Grote, Vanessa,Neud?rfl, J?rg-Martin,Goldfuss, Bernd
supporting information, p. 771 - 779 (2019/02/19)
Methyl- A nd phenyllithium aggregates with enantiopure anisyl fencholate units form after reaction of organolithium reagent with (+)-anisyl fenchol in hydrocarbon and some ethereal solvents. These carbanionic aggregates are characterized by X-ray crystal analyses and exhibit both 3:1 stoichiometry and distorted cubic Li4O3C1 cores, in which three lithium ions coordinate the carbanion (i.e., methylide or phenylide). These three lithium ions define a Lewis acidic surface (Li3), binding the carbanion and expanding with the steric demand of the carbanion (i.e., from Me: 2.62 ?2, over n-Bu: 2.65 ?2 (previous work) to Ph: 2.79 ?2). Methylation and phenylation reactions of various prochiral aldehydes employing these methyllithium and phenyllithium aggregates yield alcohols with up to 44% ee. To rationalize the formation of the mixed (carb-)anionic aggregates, aggregate formation energies, describing co-condensations of RLi (R = Me, Ph, n-Bu) and lithium fencholates, are computed for the 3:1 and 2:2 stoichiometries. These computed aggregate formation energies point to preferences for 3:1 over 2:2 aggregates, as it is also apparent from experimental aggregate formations, confirmed by X-ray crystal analyses. In close analogy to the X-ray crystal structures, the computed Li3 surfaces increase with increasing steric demand of the carbanions. The chiral, mixed (carb-)anionic RLi-fencholate aggregates hence adapt to different carbanion sized and arise not only with small (Me) or primary carbanions (n-Bu) but even with the larger secondary phenyl anion.
