53376-62-8Relevant academic research and scientific papers
Synthesis of Weinreb amides using diboronic acid anhydride-catalyzed dehydrative amidation of carboxylic acids
Shimada, Naoyuki,Takahashi, Naoya,Ohse, Naoki,Koshizuka, Masayoshi,Makino, Kazuishi
supporting information, p. 13145 - 13148 (2020/11/09)
The first successful example of the direct synthesis of Weinreb amides using catalytic hydroxy-directed dehydrative amidation of carboxylic acids using the diboronic acid anhydride catalyst is described. The methodology is applicable to the concise syntheses of eight α-hydroxyketone natural products, namely, sattabacin, 4-hydroxy sattabacin, kurasoins A and B, soraphinols A and B, and circumcins B and C.
A Ball-Milling-Enabled Reformatsky Reaction
Cao, Qun,Stark, Roderick T.,Fallis, Ian A.,Browne, Duncan L.
, p. 2554 - 2557 (2019/06/17)
An operationally simple one-jar one-step mechanochemical Reformatsky reaction using in situ generated organozinc intermediates under neat grinding conditions has been developed. Notable features of this reaction protocol are that it requires no solvent, no inert gases, and no pre-activation of the bulk zinc source. The developed process is demonstrated to have good substrate scope (39–82 % yield) and is effective irrespective of the initial morphology of the zinc source.
Cobalt-Catalyzed Alkoxycarbonylation of Epoxides to β-Hydroxyesters
Xu, Jian-Xing,Wu, Xiao-Feng
, p. 9907 - 9912 (2019/08/26)
Herein, we developed a new and practical catalytic system for the carbonylative synthesis of β-hydroxyesters. By using simple, cheap, and air-stable cobalt(II) bromide as the catalyst, combined with pyrazole and catalytic amount of manganese, active cobalt complex can be generated in situ and can catalyze various epoxides to give the corresponding β-hydroxyesters in moderate to excellent yields. Mechanism studies indicate that pyrazole plays a crucial role in this reaction. Moreover, with the addition of the catalytic amount of manganese, the active cobalt catalyst can be regenerated, which provides a possibility for reusing the cobalt catalyst.
Bu 4 N + -Controlled Addition and Olefination with Ethyl 2-(Trimethylsilyl)acetate via Silicon Activation
Das, Manas,Manvar, Atul,Fox, Ian,Roberts, Dilwyn J.,O'Shea, Donal F.
supporting information, p. 2401 - 2406 (2017/09/30)
Catalytic Bu 4 NOAc as silicon activator of ethyl 2-(trimethylsilyl)acetate, in THF, was utilized for the synthesis of β-hydroxy esters, whereas employing catalytic Bu 4 NOTMS gave α,β-unsaturated esters. The established reaction conditions were applicable to a diverse range of aromatic, heteroaromatic, aliphatic aldehydes and ketones. Reactions were achieved at room temperature without taking any of the specialized precautions that are in place for other organometallics. A stepwise olefination pathway via silylated β-hydroxy esters with subsequent elimination to form the α,β-unsaturated ester has been demonstrated. The key to selective product formation lies in use of the weaker acetate activator which suppresses subsequent elimination whereas stronger TMSO - activator (and base) facilitates both addition and elimination steps. The use of tetrabutyl ammonium salts for both acetate and trimethylsilyloxide activators provide enhanced silicon activation when compared to their inorganic cation counterparts.
Enantioselective Reduction of Ethyl 3-Oxo-5-phenylpentanoate with Whole-Cell Biocatalysts
Zadlo, Anna,Schrittwieser, Joerg H.,Koszelewski, Dominik,Kroutil, Wolfgang,Ostaszewski, Ryszard
supporting information, p. 1007 - 1011 (2016/03/01)
The biocatalytic stereoselective synthesis of a sterically demanding sec-alcohol (ethyl 3-hydroxy-5-phenylpentanoate) was investigated by starting from the corresponding prochiral ketone. Screening of a collection of microorganisms led to the identificati
A rapid and diverse construction of 6-substituted-5,6-dihydro-4-hydroxy-2- pyrones through double Reformatsky reaction
Mineno, Masahiro,Sawai, Yasuhiro,Kanno, Kazuaki,Sawada, Naotaka,Mizufune, Hideya
, p. 10921 - 10926 (2014/01/06)
A rapid and diverse synthesis of biologically important 6-substituted-5,6-dihydro-4-hydroxy-2-pyrones through a double Reformatsky reaction of aldehydes to δ-hydroxy-β-ketoesters followed by lactonization is described. Due to the high functional group tolerance and reaction site discrimination between aldehyde, nitrile, and ester groups in the substrate, the protocol can provide the dihydropyrones with bromo, nitro, carboxylic acid, and β-ketoester groups, which are suitable for the further derivatizations. Furthermore, the protocol has been successfully applied to the rapid total synthesis of naturally occurring Yangonin.
Asymmetric transfer hydrogenation of functionalized acetylenic ketones
Fang, Zhijia,Wills, Martin
, p. 8594 - 8605 (2013/09/24)
A systematic study of the asymmetric transfer hydrogenations of functionalized acetylenic ketones and diketones has been completed, together with a total synthesis of (S,S)-(-)-yashabushidiol B. In several cases, excellent enantioselectivities and yields
N-heterocyclic carbene mediated Reformatsky reaction of aldehydes with a-trimethylsilylcarbonyl compounds
Zou, Xiao-Lei,Du, Guang-Fen,Sun, Wan-Fu,He, Lin,Ma, Xiao-Wei,Gu, Cheng-Zhi,Dai, Bin
, p. 607 - 612 (2013/07/27)
N-Heterocyclic carbenes have been employed as highly efficient organocatalysts to mediate silyl-Reformatsky type reaction. In the presence of only 0.5 mol % nucleophilic carbene 1, various aldehydes coupled with α-trimethylsilylethylacetate very smoothly in DMF at room temperature to provide the corresponding β-hydroxyesters in moderate to high yields. α-Trimethylsilylketone and α-trimethylsilylamide can also undergo the addition reaction to give β-hydroxyketone and b-hydroxyamide in moderate yields.
MNBA-mediated β-lactone formation: Mechanistic studies and application for the asymmetric total synthesis of tetrahydrolipstatin
Shiina, Isamu,Umezaki, Yuma,Kuroda, Nobutaka,Iizumi, Takashi,Nagai, Shunsuke,Katoh, Takashi
experimental part, p. 4885 - 4901 (2012/07/30)
Various β-lactones were prepared from β-hydroxycarboxylic acids by intramolecular dehydration condensation using MNBA, an effective coupling reagent, along with a nucleophilic catalyst. The transition state that provides the desired 4-membered ring model system is disclosed by density functional theory (DFT) calculations, and the structural features of the transition form are discussed. This method was successfully applied to the asymmetric total synthesis of tetrahydrolipstatin (THL), an antiobestic drug used in clinical treatment to inhibit the activity of pancreatic lipase.
Gold(I)-catalyzed alkoxyhalogenation of β-hydroxy-α,α- difluoroynones
Schuler, Marie,Silva, Franck,Bobbio, Carla,Tessier, Arnaud,Gouverneur, Veronique
supporting information; experimental part, p. 7927 - 7930 (2009/05/07)
(Chemical Equation Presented) Gold standard: AuCl was found to be the only suitable catalyst for the 6-endo-dig ring closure of hydroxylated difluorinated ynones (see scheme), a class of substrates that displays low reactivity owing to the presence of the
