91748-03-7Relevant articles and documents
Enantioselective Desymmetrization of 2-Aryl-1,3-propanediols by Direct O-Alkylation with a Rationally Designed Chiral Hemiboronic Acid Catalyst That Mitigates Substrate Conformational Poisoning
Estrada, Carl D.,Ang, Hwee Ting,Vetter, Kim-Marie,Ponich, Ashley A.,Hall, Dennis G.
supporting information, (2021/04/07)
Enantioselective desymmetrization by direct monofunctionalization of prochiral diols is a powerful strategy to prepare valuable synthetic intermediates in high optical purity. Boron acids can activate diols toward nucleophilic additions; however, the design of stable chiral catalysts remains a challenge and highlights the need to identify new chemotypes for this purpose. Herein, the discovery and optimization of a bench-stable chiral 9-hydroxy-9,10-boroxarophenanthrene catalyst is described and applied in the highly enantioselective desymmetrization of 2-aryl-1,3-diols using benzylic electrophiles under operationally simple, ambient conditions. Nucleophilic activation and discrimination of the enantiotopic hydroxy groups on the diol substrate occurs via a defined chairlike six-membered anionic complex with the hemiboronic heterocycle. The optimal binaphthyl-based catalyst 1g features a large aryloxytrityl group to effectively shield one of the two prochiral hydroxy groups on the diol complex, whereas a strategically placed "methyl blocker"on the boroxarophenanthrene unit mitigates the deleterious effect of a competing conformation of the complexed diol that compromised the overall efficiency of the desymmetrization process. This methodology affords monoalkylated products in enantiomeric ratios equal or over 95:5 for a wide range of 1,3-propanediols with various 2-aryl/heteroaryl groups.
Niraparib important intermediate and enzymatic synthesis method thereof
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Paragraph 0024, (2020/05/08)
The invention discloses a niraparib important intermediate and an enzymatic synthesis method thereof. The synthesis method is as follows: taking 2-(4-nitrophenyl) dimethyl malonate as a raw material;dissolving the raw material in methanol, and adding sodi
Reducing ion channel activity in a series of 4-heterocyclic arylamide FMS inhibitors
Wilson, Kenneth J.,Illig, Carl R.,Chen, Jinsheng,Wall, Mark J.,Ballentine, Shelley K.,Desjarlais, Renee L.,Chen, Yanmin,Schubert, Carsten,Donatelli, Robert,Petrounia, Ioanna,Crysler, Carl S.,Molloy, Christopher J.,Chaikin, Margery A.,Manthey, Carl L.,Player, Mark R.,Tomczuk, Bruce E.,Meegalla, Sanath K.
scheme or table, p. 3925 - 3929 (2010/09/03)
During efforts to improve the bioavailability of FMS kinase inhibitors 1 and 2, a series of saturated and aromatic 4-heterocycles of reduced basicity were prepared and evaluated in an attempt to also improve the cardiovascular safety profile over lead ary
Facile reduction of malonate derivatives using NaBH4/Br2: an efficient route to 1,3-diols
Tudge, Matthew,Mashima, Hiroko,Savarin, Cecile,Humphrey, Guy,Davies, Ian
, p. 1041 - 1044 (2008/09/17)
Borane-dimethoxyethane generated from sodium borohydride-bromine mixtures efficiently reduces a wide range of malonate derivatives to the corresponding 1,3-diols. This new reagent system represents a milder alternative to current methods available, providing the requisite 1,3-diols in higher yields over shorter reaction times.
Unusual Tethering Effects in the Schmidt Reaction of Hydroxyalkyl Azides with Ketones: Cation-π and Steric Stabilization of a Pseudoaxial Phenyl Group
Katz, Christopher E.,Aube, Jeffrey
, p. 13948 - 13949 (2007/10/03)
The Lewis acid-promoted reactions of chiral 2-aryl-3-azido-1-propanols with 4-substituted cyclohexanones lead to iminium ethers and ultimately caprolactams (following a hydrolysis step). In this study, it is shown that these reactions afford variable ratios of products, depending on the electronic nature of the phenyl group. These results are interpreted in the context of a cation?π stabilizing effect in the product-determining reaction intermediate. Remarkably, the best selectivity was obtained when an azidopropanol reagent containing a quaternary center was used; a control experiment showed that the high selectivity observed in this result depended upon the free rotation of the pseudoaxial aromatic group in the intermediate that affords the major product. Copyright
Ferrocenyl derivatives with one, two, or three sulfur-containing arms for self-assembled monolayer formation
Hu, Jian,Mattern, Daniell Lewis
, p. 2277 - 2281 (2007/10/03)
Self-assembled monolayers of electroactive molecules can form on gold electrodes if the molecules include a sulfur-containing group to coordinate with the gold surface. We have prepared a molecule with a tripod of sulfur groups that has the potential of fixing the geometry of the molecule relative to the gold surface. The target (3) contained the good one-electron donor ferrocene connected through a benzene spacer to an isobutane tripod, with each arm of the tripod ending in a methylthio group. Analogous compounds with one (1) and two (2) coordinating arms were also prepared.
Electrogenerated Base (EG Base) Induced Hydroxymethylation of the Side Chain of Nitroalkylbenzenes with Paraformaldehyde
Torii, Sigeru,Murakami, Yasuo,Tanaka, Hideo,Okamoto, Koichi
, p. 3143 - 3147 (2007/10/02)
Hydroxymethylation of nitroalkylbenzenes with paraformaldehyde was accomplished by electrolysis in a (CH2O)n-DMF-Et4NOTs-(Pt electrode) system.The reaction was found to be catalytic (0.25 faraday/mol) and dependent on the electroreduction of formaldehyde and/or nitroalkylbenzene.A variety of nitroalkylbenzenes were transformed to their corresponding mono- and/or bishydroxymethylated derivatives in good yield.The product yield and selectivity were shown to depend on the order of reagent addition, solvent, supporting electrolyte, and structure of the starting nitroalkylbenzenes.A plausible mechanism of the generation of base catalysts (EG base) in electroreductive media is discussed.
