126266-78-2Relevant articles and documents
From Esters to Ketones via a Photoredox-Assisted Reductive Acyl Cross-Coupling Strategy
Chen, Yukun,Li, Weirong,Luo, Yixin,Qi, Xiaotian,Xi, Xiaoxiang,Xu, Minghao,Yuan, Weiming,Zhao, Hongping,Zheng, Songlin
, (2021/12/06)
A method was developed for ketone synthesis via a photoredox-assisted reductive acyl cross-coupling (PARAC) using a nickel/photoredox dual-catalyzed cross-electrophile coupling of two different carboxylic acid esters. A variety of aryl, 1°, 2°, 3°-alkyl 2-pyridyl esters can act as acyl electrophiles while N-(acyloxy)phthalimides (NHPI esters) act as 1°, 2°, 3°-radical precursors. Our PARAC strategy provides an alternative and reliable way to synthesize various sterically congested 3°-3°, 3°-2°, and aryl-3° ketones under mild and highly unified conditions, which have been otherwise difficult to access. The combined experimental and computational studies identified a Ni0/NiI/NiIII pathway for ketone formation.
Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
, p. 17887 - 17896 (2020/08/19)
An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
Electrochemical 1,4-reduction of α,β-unsaturated ketones with methanol and ammonium chloride as hydrogen sources
Huang, Binbin,Li, Yanan,Yang, Chao,Xia, Wujiong
supporting information, p. 6731 - 6734 (2019/06/17)
A sustainable, chemoselective 1,4-reduction of α,β-unsaturated ketones by means of an electrochemical method is presented, wherein the extremely inexpensive ammonium chloride (NH4Cl) is applied as the only additive. The reaction proceeds smoothly in the air at ambient temperature. Mechanistic studies reveal that both NH4Cl and solvent methanol work as hydrogen donors.
A nanoscale iron catalyst for heterogeneous direct: N - And C -alkylations of anilines and ketones using alcohols under hydrogen autotransfer conditions
Nallagangula, Madhu,Sujatha, Chandragiri,Bhat, Venugopal T.,Namitharan, Kayambu
supporting information, p. 8490 - 8493 (2019/07/22)
Here, we report a commercially available nanoscale Fe catalyst for heterogeneous direct N- and C-alkylation reactions of anilines and methyl ketones with alcohols. A hydrogen autotransfer mechanism has been found to operate in these reactions by deuterium labelling studies. In addition, dehydrogenative quinoline synthesis has been demonstrated from amino benzyl alcohols and acetophenones.
In Water and under Mild Conditions: α-Alkylation of Ketones with Alcohols by Phase-Transfer-Assisted Borrowing Hydrogen Catalysis
Rakers, Lena,Sch?fers, Felix,Glorius, Frank
supporting information, p. 15529 - 15532 (2018/10/09)
Borrowing hydrogen is a powerful and green technique that allows readily available alcohols to be used as alkylating agents and produces water as the only by-product. Nevertheless, harsh conditions such as high temperatures and organic solvents are usually required. Herein, we present a strategy to perform the α-alkylation of ketones in aqueous media at mild temperatures by combining borrowing hydrogen with phase-transfer catalysis. A broad scope of methyl ketones was functionalized with alkyl and benzyl alcohols in moderate to good yields at 40 °C. The protocol was also highly effective at large scale and room temperature.
Acceptorless dehydrogenation and dehydrogenative coupling of alcohols catalysed by protic NHC ruthenium complexes
Chang, Weihong,Gong, Xue,Wang, Shuizhong,Xiao, Ling-Ping,Song, Guoyong
supporting information, p. 3466 - 3471 (2017/04/26)
A new family of protic NHC Ru complexes ligated with a phosphine-tethered imidazole moiety were prepared, which can act as excellent catalysts for acceptorless dehydrogenation of secondary alcohols and dehydrogenative coupling of primary and secondary alcohols, thus leading to the formation of a variety of carbonyl compounds with release of H2.
Direct acylation of aryl chlorides with aldehydes by palladium-pyrrolidine Co-catalysis
Colbon, Paul,Ruan, Jiwu,Purdie, Mark,Xiao, Jianliang
supporting information; experimental part, p. 3670 - 3673 (2010/10/20)
A palladium catalyst system has been developed that allows for the direct acylation of aryl chlorides with aldehydes. The choice of ligand, as well as the presence of pyrrolidine and molecular sieves is shown to be critical to the catalysis, which appears to proceed via an enamine intermediate. The reaction was successful for a wide range of aryl chlorides and tolerant of functionality on the aldehyde component, giving easy access to alkyl aryl ketones in modest to good yields.
Efficient chemoselective biohydrogenation of 1,3-diaryl-2-propen-1-ones catalyzed by Saccharomyces cerevisiae yeasts in biphasic system
Silva, Vanessa Dutra,Stambuk, Boris Ugarte,Nascimento, Maria da Graca
experimental part, p. 157 - 163 (2010/10/19)
A series of chalcones (1-9) was synthesized by base catalyzed aldol condensation with 50-94% yields. These α,β-unsaturated carbonyl compounds were used as substrates in biotransformation reactions mediated by three industrial Saccharomyces cerevisiae strains in biphasic systems. Several reaction parameters were evaluated, such as yeast concentration, temperature, pH, substrate concentration, organic solvent, volume of aqueous and organic phases and the influence of substituent groups on chalcones 1-9. The biotransformation was chemoselective and formed only the corresponding saturated ketones. The highest conversion (>99%) to the dihydrochalcone was obtained at 30-45°C and pH above 5.5, while the cellular and substrate concentrations also showed a strong influence on the biohydrogenation reaction. Organic solvents with log. P >3.2 (hexane or heptane) were the most appropriate, and 40-80% of aqueous phase allowed the highest conversions probably by maintaining the yeast enzymes catalytically active. The influence of substituents on rings A and B of chalcones 1-9 was low and no correlation between the donor or withdrawing electron groups was observed.