- Cyanolysis of γ-Hydroxy-γ'-ketosulfones: A New Approach to γ-Sultines
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Cleavage of γ-hydroxy-γ'-ketosulfones 3 with cyanide leads to γ-ketonitriles 4 and γ-hydroxysulfinic acids 5.Compounds 5 by cyclization yield γ-sultines 6.
- Messinger, Paul,Vietinghoff-Scheel, Rudolf v.
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- Vitamin B12 Enables Consecutive Generation of Acyl and Alkyl Radicals from One Reagent
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Co complex – Cby(OMe)7 - enables consecutive generation of alkyl and acyl radicals from adequately designed carboxylic acids possessing a halogen atom in theirs structures. Mechanistic studies reveal that alkyl corrins forms at much higher rate than the respective acyl derivatives enabling selective reactions with activated olefins.
- Potrz?saj, Aleksandra,Ociepa, Micha?,Baka, Oskar,Spólnik, Grzegorz,Gryko, Dorota
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- 1-butyl-3-methylimidazolium bromide as a solvent and precatalyst for stetter reaction
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Stetter reaction between aromatic aldehydes and acrylonitrile/ethyl acrylate performing in [Bmim]Br in the presence of NaOH is described. N-Heterocyclic carbene (NHC) generates in situ is shown to be an efficient catalyst. Benzoin condensation also occured as side reaction.
- Phungpis, Baramee,Hahnvajanawong, Viwat
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p. 2028 - 2032
(2020/09/02)
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- Organic Dye-Catalyzed Intermolecular Radical Coupling of α-Bromocarbonyls with Olefins: Photocatalytic Synthesis of 1,4-Ketocarbonyls Using Air as an Oxidant
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An organic dye-catalyzed visible light-promoted ketocarbonylation protocol of vinyl arenes has been disclosed with the help of α-bromocarbonyls where aerial oxygen played a role of an oxidant to install the keto-oxygen functionality. This unique process i
- Roy Chowdhury, Soumyadeep,Singh, Deepak,Hoque, Injamam Ul,Maity, Soumitra
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p. 13939 - 13950
(2020/11/20)
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- Facile Synthesis of γ-Ketonitriles in Water via C(sp2)–H Activation of Aromatic Aldehydes over Cu?g-C3N4 under Visible-Light
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A facile C(sp2)–H activation of aldehyde under visible-light conditions using Cu?g-C3N4 as photocatalyst and water as solvent is reported. The envisaged method involves photocatalytic intermolecular Stetter reaction using
- Bhardiya, Smita R.,Rai, Ankita,Rai, Vijai K.,Sheshma, Harendra,Singh, Manorama,Verma, Fooleswar
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p. 5841 - 5846
(2020/09/21)
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- Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles
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The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional group tolerance, and use of commercially available substrates, the Pd-catalyzed addition reaction of arylboronic acid and dinitriles is expected to be significant in future synthetic procedures.
- Qi, Linjun,Li, Renhao,Yao, Xinrong,Zhen, Qianqian,Ye, Pengqing,Shao, Yinlin,Chen, Jiuxi
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p. 1097 - 1108
(2020/01/22)
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- Copper-Catalyzed Radical Cross-Coupling of Oxime Esters and Sulfinates for Synthesis of Cyanoalkylated Sulfones
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Sulfones and alkylnitriles play a significant role in both organic and medicinal chemistry, as versatile synthetic building blocks and privileged pharmacophores in many natural products and bioactive compounds. Herein, a room-temperature, copper-catalyzed radical cross-coupling of redox-active cycloketone oxime esters and sulfinate salts is described for the first time. Key to the success of this process involves catalytic generation of a cyclic iminyl radical and ensuing ring-opening C?C bond cleavage. The resultant cyanoalkyl radical is then engaged in cross-coupling with nucleophilic sulfinate to form cyanoalkylated sulfones.
- Zhou, Xue-Song,Cheng, Ying,Chen, Jun,Yu, Xiao-Ye,Xiao, Wen-Jing,Chen, Jia-Rong
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p. 5300 - 5305
(2019/11/13)
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- Copper-Catalyzed Decarboxylative Oxyalkylation of Alkynyl Carboxylic Acids: Synthesis of ?-Diketones and ?-Ketonitriles
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A novel copper-catalyzed decarboxylative oxyalkylation of alkynyl carboxylic acids with ketones and alkylnitriles via direct C(sp3)-H bond functionalization to construct new C-C bonds and C-O double bonds was developed. This transformation is featured by wide functional group compatibility and the use of readily available reagents, thus affording a general approach to ?-diketones and ?-ketonitriles. A possible mechanism is proposed.
- Li, Yi,Shang, Jia-Qi,Wang, Xiang-Xiang,Xia, Wen-Jin,Yang, Tao,Xin, Yangchun,Li, Ya-Min
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supporting information
p. 2227 - 2230
(2019/03/26)
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- Ag2CO3-mediated direct functionalization of alkyl nitriles: Facile synthesis of γ-ketonitriles through nitrile alkylation of enol acetates
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Direct C(sp3)-H functionalization of alkyl nitriles is a low toxic and facile route to nitrile-containing compounds. In this research, the Ag2CO3-mediated nitrile methylenation of enol acetates is developed to prepare γ-ketonitriles through the direct C(sp3)-H oxidative functionalization of acetonitrile. A radical pathway is proposed, and acetonitrile serves both as solvent and CN-containing radical source.
- Cheng, Pi,Wang, Wei,Wang, Lin,Zeng, Jianguo,Reiser, Oliver,Liang, Yun
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supporting information
p. 1408 - 1412
(2019/05/06)
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- Light-Driven Vitamin B12-Catalysed Generation of Acyl Radicals from 2-S-Pyridyl Thioesters
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Acyl radicals are invaluable intermediates in organic synthesis, however their generation remains challenging. Herein, we present an unprecedented light-driven, cobalt-catalysed method for the generation of acyl radicals from readily available 2-S-pyridyl thioesters. The synthetic potential of this methodology was demonstrated in the Giese-type acylation of activated olefins in the presence of heptamethyl cobyrrinate. This vitamin B12 derivative proved to be the most efficient catalyst in the studied process. The developed method features broad substrate scope (38 examples), good functional group tolerance, and mild reaction conditions. Moreover, it is easily scalable (illustrated on a 20-fold scale-up procedure), enabling its preparative use. Mechanistic studies revealed that the reaction proceeds via a radical pathway with the key steps involving the formation of an acyl-vitamin B12 complex and subsequent photolysis of the Co?C bond. (Figure presented.).
- Ociepa, Micha?,Baka, Oskar,Narodowiec, Jakub,Gryko, Dorota
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supporting information
p. 3560 - 3565
(2017/10/24)
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- Unactivated C(sp3)-H Bond Functionalization of Alkyl Nitriles with Vinylarenes and Mechanistic Studies
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The first example of a metal-free unactivated C(sp3)-H bond functionalization of alkyl nitriles with terminal vinylarenes to provide γ-ketonitrile derivatives is described. This protocol features simple operations, a broad substrate scope, and atom and step economy. In addition, Cu-catalyzed C(sp3)-H bond functionalization of azodiisobutyronitrile (AIBN) and analogues with terminal vinylarenes to generate γ-ketonitriles was also studied. A preliminary free-radical pathway was confirmed by capturing an alkyl radical, and a conjugate system was found that can stabilize radical intermediates and be in favor of this transformation. Density functional theory (DFT) calculations also provide important evidence of the free-radical pathway.
- Lan, Xing-Wang,Wang, Nai-Xing,Bai, Cui-Bing,Lan, Cui-Lan,Zhang, Tong,Chen, Shi-Lu,Xing, Yalan
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supporting information
p. 5986 - 5989
(2016/12/09)
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- Benzoin condensation and stetter reaction catalysed by N,N-dimethylbenzimidazolium iodide in [Bmim][OH]
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N,N-Dimethylbenzimidazolium iodide catalysed benzoin condensation and Stetter reaction in 1-butyl-3-methylimidazolium hydroxide [bmim][OH] which acts as a basic catalyst as well as a solvent for the reactions are described. The recycled reaction media containing benzimidazolium salt can be reused for several times without significant loss of efficiency.
- Phungpis, Baramee,Hahnvajanawong, Viwat,Theramongkol, Parinya
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p. 933 - 939
(2015/02/19)
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- Study of the chemoselectivity of Grignard reagent addition to substrates containing both nitrile and Weinreb amide functionalities
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Several substrates containing both cyano and Weinreb amide functionalities have been synthesized to study the chemoselectivity of their reactions with organomagnesium bromides (ArMgBr and RMgBr). Excellent chemoselectivity towards the Weinreb amide was observed in most cases, even in the presence of excess Grignard reagent, affording cyano ketones in good-to-excellent yields. The reactions of various substrates containing both nitrile and Weinreb amide functionalities with Grignard reagents have been studied. The Weinreb amide reacts chemoselectively with excess Grignard reagent to give the corresponding cyano ketones in good yields. This chemoselectivity has been exploited for the synthesis of a key coumarin intermediate towards the 5-lipoxygenase inhibitor MK-0633. Copyright
- Harikrishna, Kommidi,Rakshit, Ananya,Aidhen, Indrapal Singh
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p. 4918 - 4932
(2013/08/23)
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- Synthetic strategy toward γ-KETO NITRILES and their Biocatalytic conversion to asymmetric γ-lactones
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Asymmetric γ-hydroxy nitriles are valuable intermediates because hydrolysis of the nitriles can result in an intramolecular cyclization to chiral γ-lactones, which have a variety of biological uses. Starting with an assortment of different aldehydes (alkyl and aryl) a 4-step synthesis of γ-keto nitriles was developed. These prochiral substrates were then screened against a library of ketoreductases for their ability to stereoselectively reduce the carbonyl. Enzymes from the short chain dehydrogenase family showed activity and these enzymatic reactions were scaled up to produce a diverse set of chiral γ-lactones.
- Franz, Sarah E.,Watkins, Richard R.,Wright, Laura A.,Weaver, Blair A.,Hartage, Ramon C.,Ghiviriga, Ion,Gumina, Giuseppe,Feske, Brent D.
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p. 2171 - 2178
(2013/08/23)
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- A new method for the synthesis of γ-oxobutyronitriles via addition of aroyl chlorides to acrylonitrile promoted by samarium metal in DMF
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Without any pretreatment or activator, metallic samarium in DMF promotes the addition of aroyl chlorides to acrylonitrile to form γ -oxobutyronitriles.
- Liu, Yongjun,Zhang, Yongmin
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p. 163 - 164
(2007/10/03)
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- Process for preparing ketones
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Ketones are prepared by reacting an aromatic or heterocyclic aldehyde in the presence of a cyanide ion with an unsaturated compound having the formula (I): STR1 wherein R1, R2 and R3 are the same or different and are selected from the group of hydrogen, optionally substituted aliphatic, cycloaliphatic, araliphatic, aromatic, heterocyclic and carboxylic acid ester and R4 is nitrile (CN), --CO--R5 or --CO--OR5 wherein R5 is selected from the group of optionally substituted aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic and R1 and R2 and/or R1 and R3 and/or R2 and R5 or R3 and R5 together with the carbon atoms to which they are attached as substituents may also form a carbocyclic or heterocyclic ring. Ketones prepared according to the process of the invention have the formula: STR2 wherein R1 ' and R3 ' are identical or different and are selected from the group of hydrogen, lower alkyl having up to 3 C-atoms and optionally substituted phenyl; and R6 ' is optionally substituted phenyl or a pyridyl.
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