5355-61-3Relevant academic research and scientific papers
Reductive Ring-Opening 1,3-Difunctionalizations of Arylcyclopropanes with Sodium Metal
Wang, Shuo,Kaga, Atsushi,Yorimitsu, Hideki
, p. 219 - 223 (2020/11/04)
Sodium dispersion promotes reductive ring opening of arylcyclopropanes. The presence of a reduction-resistant electrophile, such as methoxypinacolatoborane, epoxide, oxetane, paraformaldehyde, or chlorotrimethylsilane, during the reductive ring opening event leads to the formation of 1,3-difunctionalized 1-arylalkanes by immediate trappings of the resulting two reactive carbanions. In particular, the ring-opening 1,3-diborylations of arylcyclopropanes afford 1,3-diborylalkanes with high syn selectivity.
Double Catalytic Kinetic Resolution (DoCKR) of Acyclic anti-1,3-Diols: The Additive Horeau Amplification
Merad, Jérémy,Borkar, Prashant,Caijo, Frédéric,Pons, Jean-Marc,Parrain, Jean-Luc,Chuzel, Olivier,Bressy, Cyril
supporting information, p. 16052 - 16056 (2017/11/21)
The concept of a synergistic double catalytic kinetic resolution (DoCKR) as described in this article was successfully applied to racemic acyclic anti-1,3-diols, a common motif in natural products. This process takes advantage of an additive Horeau amplif
Asymmetric chemoenzymatic synthesis of 1,3-diols and 2,4-disubstituted aryloxetanes by using whole cell biocatalysts
Vitale, Paola,Perna, Filippo Maria,Agrimi, Gennaro,Scilimati, Antonio,Salomone, Antonio,Cardellicchio, Cosimo,Capriati, Vito
, p. 11438 - 11445 (2016/12/16)
Regio- and stereo-selective reduction of substituted 1,3-aryldiketones, investigated in the presence of different whole cell microorganisms, was found to afford β-hydroxyketones or 1,3-diols in very good yields (up to 95%) and enantiomeric excesses (up to 96%). The enantiomerically enriched aldols, obtained with the opposite stereo-preference by baker's yeast and Lactobacillus reuteri DSM 20016 bioreduction, could then be diastereoselectively transformed into optically active syn- or anti-1,3-diols by a careful choice of the chemical reducing agent (diastereomeric ratio up to 98 : 2). The latter, in turn, were stereospecifically cyclized into the corresponding oxetanes in 43-98% yields and in up to 94% ee, thereby giving a diverse selection of stereo-defined 2,4-disubstituted aryloxetanes.
Ansa-Ruthenium(II) Complexes of R2NSO2DPEN-(CH2)n(η6-Aryl) Conjugate Ligands for Asymmetric Transfer Hydrogenation of Aryl Ketones
Ki?ic, Andrea,Stephan, Michel,Mohar, Barbara
supporting information, p. 2540 - 2546 (2015/08/18)
New 3rd generation designer ansa-ruthenium(II) complexes featuring N,C-alkylene-tethered N,N-dialkylsulfamoyl-DPEN/η6-arene ligands, exhibited good catalytic performance in the asymmetric transfer hydrogenation (ATH) of various classes of (het)aryl ketones in formic acid/triethylamine mixture. In particular, benzo-fused cyclic ketones furnished 98 to >99.9% ee using a low catalyst loading.
Asymmetric synthesis of new chiral 1,2- and 1,3-diols
Yildiz, Tülay,Yusufo?lu, Ay?e
, p. 183 - 190 (2013/07/27)
Seven chiral 1,2-diols and six chiral 1,3-diols were synthesized by the asymmetric reduction of the corresponding 1,2-diketones and 1,3-diketones using oxazaborolidine-BH3 catalyst. The 13 corresponding racemic 1,2- and 1,3-diols were synthesized by reducing the diketones with NaBH4 and they were used for determining the ee values through their chiral resolution on HPLC and GC. Five starting diketones, four racemic 1,2-diols, five chiral 1,2-diols, and two chiral 1,3-diols are novel compounds. The new chiral compounds were characterized by IR, 1H and 13C NMR, MS, and elemental analysis. The asymmetric reduction method, oxazaborolidine-BH 3, was applied to these diketones for the first time in this study. The relationship between the structure of the diketone and the yield, diastereoselectivity, and enantiomeric excess was discussed.
Selective hydroformylation of various olefins using diphosphinite ligands
Khan, Shoeb R.,Bhanage, Bhalchandra M.
, p. 313 - 317 (2013/07/04)
Novel diphosphinite ligands are synthesized by the reaction of various derivatives of 1,3-diols with chlorodiphenylphosphine. The synthesized ligands exhibited considerable impact on hydroformylation of various olefins with excellent regioselectivity toward branched aldehyde. The effect of solvent, temperature, pressure and catalyst loading on the hydroformylation reaction is also described. The synthesized diphosphinite ligands with rhodium precursor works under milder reaction conditions as compared to traditional phosphine and phosphite-based ligands. Copyright 2013 John Wiley & Sons, Ltd. A novel diphosphinite ligands are synthesized by the reaction of various derivatives of 1,3-diol with chlorodiphenylphosphine. The synthesized ligands exhibited a considerable impact on hydroformylation of various olefins with excellent regioselectivity toward branched aldehyde. The effect of solvent, temperature, pressure and catalyst loading on the hydroformylation reaction is also described. The synthesized diphosphinite ligands with Rhodium precursor works at milder reaction conditions as compared to traditional phosphine and phosphite based ligands. Copyright
Rearrangement of cyclopropylborane into boretane
Rubina, M.,Rubin, M.
, p. 807 - 821,15 (2020/09/09)
Previously unknown boron-containing four-membered unsaturated heterocycle boretane was obtained via novel thermal rearrangement of cyclopropylborane and investigated by NMR and IR spectroscopy. Formation of boretane was also confirmed through its chemical
Albumin-directed stereoselective reduction of 1,3-diketones and β-hydroxyketones to anti diols
Berti, Federico,Bincoletto, Simone,Donati, Ivan,Fontanive, Giampaolo,Fregonese, Massimo,Benedetti, Fabio
experimental part, p. 1987 - 1999 (2011/04/25)
The reduction of 1,3-diketones and β-hydroxyketones with NaBH 4 in aqueous acetonitrile is highly stereoselective in the presence of stoichiometric amounts of bovine or human albumin, giving anti 1,3-diols with d.e. up to 96%. The same reaction, without albumin, gives syn and anti 1,3-diols in approximately 1:1 ratio. The presence of an aromatic carbonyl group is essential for diastereoselectivity in the NaBH4/albumin reduction of both 1,3-diketones and β-hydroxyketones. Thus, 3-hydroxy-1-(p-tolyl)-1- butanone is stereoselectively reduced in the presence of albumin, while reduction of its isomer 4-(p-tolyl)-4-hydroxy-2-butanone is not stereoselective. The albumin-controlled reduction is not stereospecific as both enantiomers of 1-aryl-3-hydroxy-1-butanones are reduced to diols with identical stereoselectivities. Circular dichroism of the bound substrates confirms that aromatic ketones are recognized by the protein's IIA binding site. Binding studies also suggest that 1,3-diketones are recognized in their enol form. From the effect of pH on binding of a diketone it is concluded that, in the complex with the substrate, ionizable residues His242 and Lys199 are in the neutral and protonated forms, respectively. A homology model of BSA was obtained and docking of model substrates confirms the preference of the protein for aromatic ketones. Modelling of the complexes with the substrates also allows us to propose a mechanism for the reduction of 1,3-diketones in which the chemoselective reduction of the first (aliphatic) carbonyl is followed by the diastereoselective reduction of the second (aromatic) carbonyl. The role of albumin is thus a combination of chemo- and stereocontrol.
A radical-anion chain mechanism following dissociative electron transfer reduction of the model prostaglandin endoperoxide, 1,4-diphenyl-2,3- dioxabicyclo[2.2.1]heptane
Magri, David C.,Workentin, Mark S.
body text, p. 3354 - 3361 (2009/02/05)
The model prostaglandin endoperoxide, 1,4-diphenyl-2,3-dioxabicyclo[2.2.1] heptane (3), was investigated in N,N-dimethylformamide at a glassy carbon electrode using various electrochemical techniques. Reduction of 3 occurs by a concerted dissociative electron transfer (ET) mechanism. Electrolysis at -1.6 V yields 1,3-diphenyl-cyclopentane-cis-1,3-diol in 97% by a two-electron mechanism; however, in competition with the second ET from the electrode, the resulting distonic radical-anion intermediate undergoes a β-scission fragmentation. The rate constant for the heterogeneous ET to the distonic radical-anion is estimated to occur on the order of 2 × 107 s-1. In contrast, electrolyses conducted at potentials more negative than -2.1 V yield a mixture of primary and secondary electrolysis products including 1,3-diphenyl-cyclopentane-cis-1,3-diol, 1,3-diphenyl-1,3-propanedione, trans-chalcone and 1,3-diphenyl-1,3-hydroxypropane by a mechanism involving less than one electron equivalent. These observations are rationalized by a catalytic radical-anion chain mechanism, which is dependent on the electrode potential and the concentration of weak non-nucleophilic acid. A thermochemical cycle for calculating the driving force for β-scission fragmentation from oxygen-centred biradicals and analogous distonic radical-anions is presented and the results of the calculations provide insight into the reactivity of prostaglandin endoperoxides.
1,3-Diol synthesis via controlled, radical-mediated C-H functionalization
Chen, Ke,Richter, Jeremy M.,Baran, Phil S.
, p. 7247 - 7249 (2008/12/21)
The invention of a method for the synthesis of 1,3-diols from the corresponding alcohols is described, via controlled, radical-mediated C-H functionalization. The sequence described herein entails near quantitative conversion to the corresponding trifluoroethyl carbamate, followed by a variant of the Hofmann-Loffler-Freytag reaction, cyclization, and hydrolysis to provide the 1,3-diols. In addition to the 10 examples presented herein, the syntheses of four natural products are facilitated by this directed oxyfunctionalization. This methodology is demonstrated to be orthogonal to other known C-H oxidations. Finally, this sequence is efficient, practical, inexpensive, and scalable. Copyright
