2325-10-2Relevant articles and documents
Osmium Replica of Mesoporous Silicate MCM-48: Efficient and Reusable Catalyst for Oxidative Cleavage and Dihydroxylation Reactions
Kwangyeol, Lee,Kim, Yong-Ho,Han, Soo Bong,Kang, Hongkyu,Park, Soyoung,Seo, Won Seok,Park, Joon T.,Kim, Bongsoo,Chang, Sukbok
, p. 6844 - 6845 (2003)
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A stereoselective, tandem [2+2] photocycloaddition-hydrolysis route to aldol-type adducts
Abe, Manabu,Ikeda, Masayuki,Nojima, Masatomo
, p. 3261 - 3266 (1998)
Photocycloadditions of aromatic aldehydes 2a-e with cyclic ketene silyl acetals 1a-e have been investigated. Regio-and exo-selective formation of the bicyclic 2-alkoxyoxetanes 3 was observed in high yields. Hydrolysis of the acid-labile oxetanes 3 with neutral water was efficiently achieved to give aldol-type adducts 4 (threo-selective formations).
Catalytic asymmetric dihydroxylation of alkenes using silica gel supported cinchona alkaloid
Lohray,Nandanan,Bhushan, Vidya
, p. 2805 - 2808 (1996)
Immobilization of 3,6-bis(9-O-dihydroquinyl)pyridazine and 3,6-bis(9-O-dihydroquinidyl) pyridazine on silica gel support has been reported. The use of immobilized auxiliary has lead to comparable rate with that of the homogeneous catalytic AD of alkenes, however with lower ee.
A free ligand for the asymmetric dihydroxylation of olefins utilizing one-phase catalysis and two-phase separation
Kuang, Yong-Qing,Zhang, Sheng-Yong,Jiang, Ru,Wei, Ling-Ling
, p. 3669 - 3671 (2002)
A free cinchona alkaloid derivative, which can be recovered and reused in the same way as the reported soluble polymer-supported cinchona alkaloid-derived ligands, was applied to the homogeneous asymmetric dihydroxylation of olefins. The molar ratio of ligand/olefin was 5%, being much lower than that required for the corresponding soluble polymer-supported ligands (10-25%). Yields of 82-93% and ees of 89-99% have been obtained.
A novel chemoentrapment approach for supportless recycling of a catalyst: Catalytic asymmetric dihydroxylation
Lee, Daewon,Lee, Honggeun,Kim, Seyoung,Yeom, Chang-Eun,Kim, B. Moon
, p. 1021 - 1024 (2006)
A simple method of recycling a metal catalyst through chemoentrapment in an aqueous layer using ethyl vinyl ether has been developed. Using this new methodology, a highly efficient, filtration-free recycling of osmium for catalytic asymmetric dihydroxylation was accomplished. By means of the formation of a water-soluble OsO42- using EVE, AD reactions of mono- and disubstituted olefins with 1 mol % of OsO4 proceeded for up to 9 cycles without any loss of yields and enantioselectivities.
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Ott
, p. 47,50 (1930)
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Osmium-catalyzed asymmetric dihydroxylation of olefins using chiral isoxazolidine ligands
Imada,Saito,Kawakami,Murahashi
, p. 5081 - 5084 (1992)
Chiral isoxazolidines, which are readily obtained by 1,3-dipolar cycloadditions of nitrones with olefins, are found to be effective chiral ligands for osmium-catalyzed asymmetric dihydroxylations of olefins.
A Solid-to-Solid Asymmetric Dihydroxylation Procedure for Kilogram-Scale Preparation of Enantiopure Hydrobenzoin
Wang, Zhi-Min,Sharpless, K. Barry
, p. 8302 - 8303 (1994)
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Unexpectedly superior enantioselectivity for trans-stilbene cis-dihydroxylation over anchored triosmium carbonyl species in confined Al-MCM-41 channels
Caps, Valerie,Paraskevas, Ioannis,Tsang, Shik Chi
, p. 1781 - 1783 (2005)
Superior enantioselectivity in the dihydroxylation of trans-stilbene catalysed by anchored triosmium carbonyl species without using a chiral modifier is observed inside sterically congested MCM-41 channels; this effect is more pronounced through the introduction of surface Al sites into the silicate. The Royal Society of Chemistry 2005.
(S)-Tetrahydro-5-oxo-2-furancarboxylic Acid: A Chiral Derivatizing Reagent for Asymmetric Alcohols
Doolittle, R. E.,Heath, R. R.
, p. 5041 - 5050 (1984)
The use of (S)-tetrahydro-5-oxo-2-furancarboxylic (TOF) acid as a potential derivatizing reagent for the determination of the enantiomeric composition of chiral alcohols was investigated.A series of chiral alcohols of widely varying structural type were derivatized with this acid and compared with two widely used acids (S)-α-acetoxypropanoic and (S)-α-methoxy-α-(trifluormethyl)phenylacetic.The resolution of the diastereomeric esters was measured on five different cappillary gas chromatographic (CGC) columns and one high-performance liquid chromatographic (HPLC) column.The 13C NMR spectra of these derivatives were recorded and examined for possible correlations between configuration and carbon chemical shift values.The chromatographic data provide a starting point for the selection of a derivatizing agent and column combination applicable to the CGC analysis of chiral alcohol enantiomeric purity, and the HPLC data allow selection of a derivatizing agent and solvent system for the HPLC analytical or preparative resolution of a chiral alcohol.The 13C NMR data provide information applicable to the assignment of the configuration to the resolved diastereomers.
Computational Design of Enantiocomplementary Epoxide Hydrolases for Asymmetric Synthesis of Aliphatic and Aromatic Diols
Arabnejad, Hesam,Bombino, Elvira,Colpa, Dana I.,Jekel, Peter A.,Trajkovic, Milos,Wijma, Hein J.,Janssen, Dick B.
, p. 1893 - 1904 (2020)
The use of enzymes in preparative biocatalysis often requires tailoring enzyme selectivity by protein engineering. Herein we explore the use of computational library design and molecular dynamics simulations to create variants of limonene epoxide hydrolas
Engineering Homochiral Metal-Organic Frameworks by Spatially Separating 1D Chiral Metal-Peptide Ladders: Tuning the Pore Size for Enantioselective Adsorption
Stylianou, Kyriakos C.,G?mez, Laura,Imaz, Inhar,Verdugo-Escamilla, Crist?bal,Ribas, Xavi,Maspoch, Daniel
, p. 9964 - 9969 (2015)
The reaction of the chiral dipeptide glycyl-L(S)-glutamate with CoII ions produces chiral ladders that can be used as rigid 1D building units. Spatial separation of these building units with linkers of different lengths allows the engineering of homochiral porous MOFs with enhanced pore sizes, pore volumes, and surface areas. This strategy enables the synthesis of a family of isoreticular MOFs, in which the pore size dictates the enantioselective adsorption of chiral molecules (in terms of their size and enantiomeric excess).
Manganese-promoted, titanocene-catalyzed stereoselective pinacol coupling of aldehydes
Dunlap, Melinda S.,Nicholas, Kenneth M.
, p. 1097 - 1106 (1999)
Aromatic and aliphatic aldehydes undergo pinacol coupling when treated with Mn/Me3SiCl in the presence of Cp2TiCl2 as catalyst. Good yields of bis-silyl pinacol ethers are obtained with varying degrees of diastereoselectivity. Enantioselective pinacolization has been achieved using an enantiomerically enriched catalyst.
Sodium borohydride reduction of aldehydes and ketones in the recyclable ionic liquid [bmim]PF6
Howarth,James,Ryan
, p. 2935 - 2938 (2001)
In our exploration of the new ionic liquid solvents as possible replacements for classical organic solvents, we have found that the reduction of aldehydes and ketones with NaBH4 in the ionic liquid [bmim]PF6 can be achieved. The ionic liquid can be recycled, and in some cases the product alcohol may be distilled directly from the ionic liquid eliminating classical organic solvents entirely.
Conjugated polymers as photoredox catalysts: A new catalytic system using visible light to promote aryl aldehyde pinacol couplings
Rouch, William D.,Zhang, Miao,McCulla, Ryan D.
, p. 4942 - 4945,4 (2012)
The conjugated polymer poly-(p)-phenylene (PPP) was synthesized and used as a photoredox catalyst to promote pinacol coupling of aryl-aldehydes with visible light. The reaction required the use of a sacrificial electron donor (Et3N), and was accelerated by the addition of Lewis and Bronsted acids. A distinct advantage of this photocatalytic system is the robust nature of the system, which is not overly sensitive to impurities, oxygen, or temperature, and proceeds cleanly with few side reactions. As a comparison with the PPP system, the reactivity of Ru(bpy)3Cl2, a popular photoredox catalyst was compared. The PPP system was superior to the Ru(bpy)3Cl2 for the pinacol couplings in both rate and yield.
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Puglisi et al.
, p. 279 (1969)
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Metal-free thermal organocatalytic pinacol coupling of arylaldehydes using an isonicotinate catalyst with bis(pinacolato)diboron
Hanaya, Kengo,Higashibayashi, Shuhei,Sugai, Takeshi,Yasui, Masamichi
, p. 24652 - 24655 (2021/07/29)
The metal-free thermal organocatalytic pinacol coupling of arylaldehydes has been developed. The intermolecular coupling of arylaldehydes catalyzed byt-butyl isonicotinate with bis(pinacolato)diboron as the co-reducing agent afforded 1,2-diphenylethane-1,2-diols. This reaction was also applicable to the intramolecular coupling of 1,1′-biphenyl-2,2′-dicarbaldehydes to afford 9,10-dihydrophenanthrene-9,10-diols. Various functional groups were tolerated under this coupling condition.
Electrochemical Arylation of Aldehydes, Ketones, and Alcohols: from Cathodic Reduction to Convergent Paired Electrolysis
Zhang, Sheng,Li, Lijun,Li, Jingjing,Shi, Jianxue,Xu, Kun,Gao, Wenchao,Zong, Luyi,Li, Guigen,Findlater, Michael
supporting information, p. 7275 - 7282 (2021/03/01)
Arylation of carbonyls, one of the most common approaches toward alcohols, has received tremendous attention, as alcohols are important feedstocks and building blocks in organic synthesis. Despite great progress, there is still a great gap to develop an ideal arylation method featuring mild conditions, good functional group tolerance, and readily available starting materials. We now show that electrochemical arylation can fill the gap. By taking advantage of synthetic electrochemistry, commercially available aldehydes (ketones) and benzylic alcohols can be readily arylated to provide a general and scalable access to structurally diverse alcohols (97 examples, >10 gram-scale). More importantly, convergent paired electrolysis, the ideal but challenging electrochemical technology, was employed to transform low-value alcohols into more useful alcohols. Detailed mechanism study suggests that two plausible pathways are involved in the redox neutral α-arylation of benzylic alcohols.
