37778-99-7Relevant articles and documents
Chelation and Stereodirecting Group Effects on Regio- And Diastereoselective Samarium(II)-Water Allylic Benzoate Reductions
Leitch, Michael A.,O'Neil, Gregory W.,Stockdale, Trevor F.
, p. 1544 - 1560 (2020)
SmI 2 (H 2 O) n reductions of allylic benzoates adjacent to a trisubstituted alkene occur in high yields with complete regioselectivity and good diastereoselectivity (up to 90:10) for substrates containing properly positioned stereodirecting- and chelating groups. The outcome of these reactions can be rationalized by ring conformation considerations of a proposed chelated organosamarium intermediate, and a mechanism involving intramolecular protonation by a samarium-bound water.
Integrated Experimental and Computational Studies on the Organocatalytic Kinetic Resolution of β-Unfunctionalized Primary Alcohols Using a Chiral 1,2-Diamine: The Importance of Noncovalent Interactions
Mori, Seiji,Ojima, Kohei,Oriyama, Takeshi,Sakai, Naoki
supporting information, p. 4468 - 4475 (2022/03/14)
The enantioselective kinetic resolution of β-unfunctionalized primary alcohols with benzoyl chloride was carried out in the presence of a catalytic amount of a novel chiral 1,2-diamine derived from (S)-proline. Several valuable chiral 2-substituted propan-1-ols were obtained with good enantioselectivities. Density functional theory calculations revealed that the noncovalent interaction, such as CH-πinteraction, is crucial for the enantioselectivity of the resolution. This study was conducted through an interplay between experiment and computation.
Structural Elucidation of the Mechanism of Molecular Recognition in Chiral Crystalline Sponges
Fairen-Jimenez, David,Zaworotko, Michael J.,Zhang, Shi-Yuan
supporting information, p. 17600 - 17606 (2020/08/12)
To gain insight into chiral recognition in porous materials we have prepared a family of fourth generation chiral metal–organic frameworks (MOFs) that have rigid frameworks and adaptable (flexible) pores. The previously reported parent material, [Co2(S-mandelate)2(4,4′-bipyridine)3](NO3)2, CMOM-1S, is a modular MOF; five new variants in which counterions (BF4?, CMOM-2S) or mandelate ligands are substituted (2-Cl, CMOM-11R; 3-Cl, CMOM-21R; 4-Cl, CMOM-31R; 4-CH3, CMOM-41R) and the existing CF3SO3? variant CMOM-3S are studied herein. Fine-tuning of pore size, shape, and chemistry afforded a series of distinct host–guest binding sites with variable chiral separation properties with respect to three structural isomers of phenylpropanol. Structural analysis of the resulting crystalline sponge phases revealed that host–guest interactions, guest–guest interactions, and pore adaptability collectively determine chiral discrimination.
Mild Iridium-Catalysed Isomerization of Epoxides. Computational Insights and Application to the Synthesis of β-Alkyl Amines
Cabré, Albert,Cabezas-Giménez, Juanjo,Sciortino, Giuseppe,Ujaque, Gregori,Verdaguer, Xavier,Lledós, Agustí,Riera, Antoni
supporting information, p. 3624 - 3631 (2019/07/10)
The isomerization of epoxides to aldehydes using the readily available Crabtree's reagent is described. The aldehydes were transformed into synthetically useful amines by a one-pot reductive amination using pyrrolidine as imine-formation catalyst. The reactions worked with low catalyst loadings in very mild conditions. The procedure is operationally simple and tolerates a wide range of functional groups. A DFT study of its mechanism is presented showing that the isomerization takes place via an iridium hydride mechanism with a low energy barrier, in agreement with the mild reaction conditions. (Figure presented.).
Identification of an Esterase Isolated Using Metagenomic Technology which Displays an Unusual Substrate Scope and its Characterisation as an Enantioselective Biocatalyst
Gavin, Declan P.,Murphy, Edel J.,Foley, Aoife M.,Castilla, Ignacio Abreu,Reen, F. Jerry,Woods, David F.,Collins, Stuart G.,O'Gara, Fergal,Maguire, Anita R.
, p. 2466 - 2474 (2019/03/11)
Evaluation of an esterase annotated as 26D isolated from a marine metagenomic library is described. Esterase 26D was found to have a unique substrate scope, including synthetic transformations which could not be readily effected in a synthetically useful manner using commercially available enzymes. Esterase 26D was more selective towards substrates which had larger, more sterically demanding substituents (i. e. iso-propyl or tert-butyl groups) on the β-carbon, which is in contrast to previously tested commercially available enzymes which displayed a preference for substrates with sterically less demanding substituents (e.g. methyl group) at the β-carbon. (Figure presented.).
Highly Enantioselective Catalytic Kinetic Resolution of α-Branched Aldehydes through Formal Cycloaddition with Homophthalic Anhydrides
Farid, Umar,Aiello, Maria Luisa,Connon, Stephen J.
, p. 10074 - 10079 (2019/07/18)
A new catalytic methodology was developed to promote an efficient one-pot kinetic resolution of racemic aldehydes with selectivity (s*) of up to 91 (99:1 d.r., >99 % ee) in a cycloaddition reaction with enolizable anhydrides to afford dihydroisocoumarin products (a core prevalent in natural products and molecules of medicinal interest) containing three contiguous stereocentres.
One-Pot Absolute Stereochemical Identification of Alcohols via Guanidinium Sulfate Crystallization
Brummel, Beau R.,Lee, Kinsey G.,McMillen, Colin D.,Kolis, Joseph W.,Whitehead, Daniel C.
, p. 9622 - 9627 (2019/12/02)
A novel technique for the absolute stereochemical determination of alcohols has been developed that uses crystallization of guanidinium salts of organosulfates. The simple one-pot, two-step process leverages facile formation of guandinium organosulfate single crystals for the straightforward determination of the absolute stereochemistry of enantiopure alcohols by means of X-ray crystallography. The strong hydrogen bonding network drives the stability of the crystal lattice and allows for a diverse range of organic alcohol substrates to be analyzed.
Biocatalytic Parallel Interconnected Dynamic Asymmetric Disproportionation of α-Substituted Aldehydes: Atom-Efficient Access to Enantiopure (S)-Profens and Profenols
Tassano, Erika,Faber, Kurt,Hall, Mélanie
supporting information, p. 2742 - 2751 (2018/07/29)
The biocatalytic asymmetric disproportionation of aldehydes catalyzed by horse liver alcohol dehydrogenase (HLADH) was assessed in detail on a series of racemic 2-arylpropanals. Statistical optimization by means of design of experiments (DoE) allowed the identification of critical interdependencies between several reaction parameters and revealed a specific experimental window for reaching an ′optimal compromise′ in the reaction outcome. The biocatalytic system could be applied to a variety of 2-arylpropanals and granted access in a redox-neutral manner to enantioenriched (S)-profens and profenols following a parallel interconnected dynamic asymmetric transformation (PIDAT). The reaction can be performed in aqueous buffer at ambient conditions, does not rely on a sacrificial co-substrate, and requires only catalytic amounts of cofactor and a single enzyme. The high atom-efficiency was exemplified by the conversion of 75 mM of rac-2-phenylpropanal with 0.03 mol% of HLADH in the presence of ～0.013 eq. of oxidized nicotinamide adenine dinucleotide (NAD+), yielding 28.1 mM of (S)-2-phenylpropanol in 96% ee and 26.5 mM of (S)-2-phenylpropionic acid in 89% ee, in 73% overall conversion. Isolated yield of 62% was obtained on 100 mg-scale, with intact enantiopurities. (Figure presented.).
A KIT FOR DETERMINING THE ABSOLUTE CONFIGURATION OF ALCOHOLS USING A COMPETING ENANTIOSELECTIVE CONVERSION APPROACH
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Paragraph 0036; 0055, (2018/06/06)
Provided herein is a kit for the determination of the absolute configuration of alcohols of a competing enantioselective conversion approach.
Deaminative Borylation of Aliphatic Amines Enabled by Visible Light Excitation of an Electron Donor–Acceptor Complex
Sandfort, Frederik,Strieth-Kalthoff, Felix,Klauck, Felix J. R.,James, Michael J.,Glorius, Frank
supporting information, p. 17210 - 17214 (2018/11/10)
A deaminative strategy for the borylation of aliphatic primary amines is described. Alkyl radicals derived from the single-electron reduction of redox-active pyridinium salts, which can be isolated or generated in situ, were borylated in a visible light-mediated reaction with bis(catecholato)diboron. No catalyst or further additives were required. The key electron donor–acceptor complex was characterized in detail by both experimental and computational investigations. The synthetic potential of this mild protocol was demonstrated through the late-stage functionalization of natural products and drug molecules.
