19347-08-1Relevant articles and documents
NMR determination of absolute configuration of α-acyloxy ketones
Jullian, Jean-Christophe,Franck, Xavier,Latypov, Shamil,Hocquemiller, Reynald,Figadere, Bruno
, p. 963 - 966 (2003)
Determination of the absolute configuration of several acyclic α-acyloxy-ketones, and δ-ketobutanolides, in the presence of a chiral solvating agent, by low temperature and low concentration 1H NMR analysis, is reported.
Formal Fluorinative Ring Opening of 2-Benzoylpyrrolidines Utilizing [1,2]-Phospha-Brook Rearrangement for Synthesis of 2-Aryl-3-fluoropiperidines
Kondoh, Azusa,Ojima, Rihaku,Terada, Masahiro
supporting information, p. 7894 - 7899 (2021/10/20)
A ring expansion of 2-benzoylpyrrolidines, which involves the formal fluorinative ring opening utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis and a subsequent intramolecular reductive amination, was developed. The operationally simple three-step protocol provides an efficient access to 2-aryl-3-fluoropiperidines. The methodology was further applied to the syntheses of azepanes and tetrahydroquinolines.
Sulfur-mediated difunctionalization of internal and terminal alkynes for the synthesis of α-acetoxy ketones
Li, Pingfan,Zhang, Zhong
, (2020/02/13)
The sulfur-mediated difunctionalization of alkynes is reported to give α-acetoxy ketones in a one-pot operation under mild conditions with 19–92% yield. By using wet potassium acetate as both the aqueous base and nucleophilic reagent, both terminal alkynes and internal alkynes could be converted into the α-acetoxy ketone products.
Continuous-Flow Electrochemical Generator of Hypervalent Iodine Reagents: Synthetic Applications
Elsherbini, Mohamed,Winterson, Bethan,Alharbi, Haifa,Folgueiras-Amador, Ana A.,Génot, Célina,Wirth, Thomas
supporting information, p. 9811 - 9815 (2019/06/24)
An efficient and reliable electrochemical generator of hypervalent iodine reagents has been developed. In the anodic oxidation of iodoarenes to hypervalent iodine reagents under flow conditions, the use of electricity replaces hazardous and costly chemical oxidants. Unstable hypervalent iodine reagents can be prepared easily and coupled with different substrates to achieve oxidative transformations in high yields. The unstable, electrochemically generated reagents can also easily be transformed into classic bench-stable hypervalent iodine reagents through ligand exchange. The combination of electrochemical and flow-chemistry advantages largely improves the ecological footprint of the overall process compared to conventional approaches.
Asymmetric Oxidation of Enol Derivatives to α-Alkoxy Carbonyls Using Iminium Salt Catalysts: A Synthetic and Computational Study
Page, Philip C. Bulman,Almutairi, Saud M.,Chan, Yohan,Stephenson, G. Richard,Gama, Yannick,Goodyear, Ross L.,Douteau, Alice,Allin, Steven M.,Jones, Garth A.
, p. 544 - 559 (2019/01/11)
We report herein the first examples of asymmetric oxidation of enol ether and ester substrates using iminium salt organocatalysis, affording moderate to excellent enantioselectivities of up to 98% ee for tetralone-derived substrates in the α-hydroxyketone products. A comprehensive density functional theory study was undertaken to interpret the competing diastereoisomeric transition states in this example in order to identify the origins of enantioselectivity. The calculations, performed at the B3LYP/6-31G(D) level of theory, gave good agreement with the experimental results, in terms of the magnitude of the effects under the specified reaction conditions, and in terms of the preferential formation of the (R)-enantiomer. Just one of the 30 characterized transition states dominates the enantioselectivity, which is attributed to the adoption of an orientation relative to stereochemical features of the chiral controlling element that combines a CH interaction between a CH2 group in the substrate and one of the aromatic rings of the biaryl section of the chiral auxiliary with a good alignment of the acetoxy group with the other biaryl ring, and places the smallest substituent on the alkene (a hydrogen atom) in the most sterically hindered position.
Expanding the Substrate Specificity of Thermoanaerobacter pseudoethanolicus Secondary Alcohol Dehydrogenase by a Dual Site Mutation
Musa, Musa M.,Bsharat, Odey,Karume, Ibrahim,Vieille, Claire,Takahashi, Masateru,Hamdan, Samir M.
, p. 798 - 805 (2018/02/21)
Here, we report the asymmetric reduction of selected phenyl-ring-containing ketones by various single- and dual-site mutants of Thermoanaerobacter pseudoethanolicus secondary alcohol dehydrogenase (TeSADH). The further expansion of the size of the substrate binding pocket in the mutant W110A/I86A not only allowed the accommodation of substrates of the single mutants W110A and I86A within the expanded active site but also expanded the substrate range of the enzyme to ketones bearing two sterically demanding groups (bulky–bulky ketones), which are not substrates for the TeSADH single mutants. We also report the regio- and enantioselective reduction of diketones with W110A/I86A TeSADH and single TeSADH mutants. The double mutant exhibited dual stereopreference to generate the Prelog products most of the time and the anti-Prelog products in a few cases.
Iodine Monoacetate for Efficient Oxyiodinations of Alkenes and Alkynes
Hokamp, Tobias,Storm, Alena Therese,Yusubov, Mekhman,Wirth, Thomas
supporting information, p. 415 - 418 (2017/10/30)
A novel and inexpensive, environmentally friendly method for the preparation of iodine monoacetate is presented using iodine and Oxone in acetic acid/acetic anhydride. The reagent is used in a highly efficient approach for the regio- and diastereoselective iodo-acetoxylation of alkenes and alkynes in a simple one-pot process.
Metal-free one-pot α-benzoxylation of benzylic alcohols with acids or aldehydes
Zhu, Yefu,Zheng, Yong,Song, Weibin,Wei, Bole,Xuan, Lijiang
supporting information, p. 368 - 371 (2018/01/04)
A metal-free strategy has been developed for α-benzoxylation of benzylic alcohols with acids or aldehydes. The reaction proceeds via sequential oxidation and α-benzoxylation in one pot. Importantly, the reactions are performed in metal-free condition and utilize cheap aqueous TBHP as an oxidant, affording α-benzoxy ketones in moderate to good yields.
Electrocatalytic Dehydrogenative Esterification of Aliphatic Carboxylic Acids: Access to Bioactive Lactones
Zhang, Sheng,Lian, Fei,Xue, Mengyu,Qin, Tengteng,Li, Lijun,Zhang, Xu,Xu, Kun
supporting information, p. 6622 - 6625 (2017/12/26)
A scalable and efficient electrocatalytic dehydrogenative esterification is reported. With an indirect electrolysis strategy, both intra- and intermolecular-type reactions were amenable to this practical method. With n-Bu4NI as the catalyst, un
PhI(OAc)2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones
Chen, Ming,Zhang, Wei,Ren, Zhi-Hui,Gao, Wen-Yun,Wang, Yao-Yu,Guan, Zheng-Hui
, p. 761 - 768 (2017/06/05)
Umpolung is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy ketones in good to excellent yields. PhI(OAc)2 serves as a source of acetoxy in the reaction.
