- Stepwise benzylic oxygenation via uranyl-photocatalysis
-
Stepwise oxygenation at the benzylic position (1°, 2°, 3°) of aromatic molecules was comprehensively established under ambient conditions via uranyl photocatalysis to produce carboxylic acids, ketones, and alcohols, respectively. The accuracy of the stepwise oxygenation was ensured by the tunability of catalytic activity in uranyl photocatalysis, which was adjusted by solvents and additives demonstrated through Stern–Volmer analysis. Hydrogen atom transfer between the benzylic position and the uranyl catalyst facilitated oxygenation, further confirmed by kinetic studies. Considerably improved efficiency of flow operation demonstrated the potential for industrial synthetic application.
- Hu, Deqing,Jiang, Xuefeng
-
supporting information
p. 124 - 129
(2022/01/19)
-
- Metal-free enaminone C-N bond cyanation for the stereoselective synthesis of (E)- And (Z)-β-cyano enones
-
A highly practical method for C-CN bond formation by C-N bond cleavage on enaminones leading to the efficient synthesis of β-cyano enones is developed. The reactions take place efficiently to provide (E)-β-cyano enones with only a molecular iodine catalyst. In addition, the additional employment of oxalic acid enables the selective synthesis of (Z)-β-cyano enones.
- Liu, Ting,Liu, Yunyun,Wan, Jie-Ping
-
supporting information
p. 9112 - 9115
(2021/09/14)
-
- Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst: Applications and mechanism thereof
-
We detail a strategy that uses a commercially available nucleophilic organic catalyst to generate acyl and carbamoyl radicals upon activation of the corresponding chlorides and anhydrides via a nucleophilic acyl substitution path. The resulting nucleophilic radicals are then intercepted by a variety of electron-poor olefins in a Giese-type addition process. The chemistry requires low-energy photons (blue LEDs) to activate acyl and carbamoyl radical precursors, which, due to their high reduction potential, are not readily prone to redox-based activation mechanisms. To elucidate the key mechanistic aspects of this catalytic photochemical radical generation strategy, we used a combination of transient absorption spectroscopy investigations, electrochemical studies, quantum yield measurements, and the characterization of key intermediates. We identified a variety of off-the-cycle intermediates that engage in a light-regulated equilibrium with reactive radicals. These regulated equilibriums cooperate to control the overall concentrations of the radicals, contributing to the efficiency of the overall catalytic process and facilitating the turnover of the catalyst. This journal is
- Balletti, Matteo,De Pedro Beato, Eduardo,Mazzarella, Daniele,Melchiorre, Paolo
-
p. 6312 - 6324
(2020/08/24)
-
- A Photochemical Organocatalytic Strategy for the α-Alkylation of Ketones by using Radicals
-
Reported herein is a visible-light-mediated radical approach to the α-alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2-based activation of alkyl halides and blue light irradiation. The resulting open-shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl halides through a traditional two-electron path. The mild reaction conditions allowed functionalization of the α position of ketones with functional groups that are not compatible with classical anionic strategies. In addition, the redox-neutral nature of this process makes it compatible with a cinchona-based primary amine catalyst, which was used to develop a rare example of enantioselective organocatalytic radical α-alkylation of ketones.
- Goti, Giulio,Melchiorre, Paolo,O?eka, Maksim,Schweitzer-Chaput, Bertrand,Spinnato, Davide
-
supporting information
p. 9485 - 9490
(2020/04/09)
-
- Preparation method of alkyl nitrile compound
-
The invention discloses a preparation method of an alkyl nitrile compound shown as formula I. The preparation method comprises the following step: in a solvent, in the presence of an additive, carrying out substitution reaction as shown in the specification on a cyanation reagent and an alkyl halide shown as formula II to obtain the alkyl nitrile compound shown as formula I, wherein the cyanationreagent is Zn (CN) 2 and/or Cu (CN) 2; the additive is one or more of an inorganic base, an organic base and a quaternary ammonium salt.
- -
-
Paragraph 0154-0156
(2020/05/14)
-
- Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles
-
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
-
p. 1097 - 1108
(2020/01/22)
-
- 1-butyl-3-methylimidazolium bromide as a solvent and precatalyst for stetter reaction
-
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
-
p. 2028 - 2032
(2020/09/02)
-
- Facile Synthesis of γ-Ketonitriles in Water via C(sp2)–H Activation of Aromatic Aldehydes over Cu?g-C3N4 under Visible-Light
-
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
-
p. 5841 - 5846
(2020/09/21)
-
- A Novel Ketonitrile Synthesis by Palladium-Catalyzed Carbonylative Coupling Reactions of Amides with Arylboronic Acids
-
A novel, efficient, and simple procedure to synthesize diverse ketonitriles by palladium-catalyzed Suzuki coupling of amides through N–C cleavage has been developed. This procedure features mild conditions, a broad substrate scope, and easily prepared substrates, providing a simple and efficient access to a variety of ketonitriles.
- Mai, Wen-Peng,Liu, Yang,Sui, Hong-Dai,Xiao, Yong-Mei,Mao, Pu,Lu, Kui
-
supporting information
p. 7814 - 7819
(2019/12/24)
-
- Radical cyanomethylation via vinyl azide cascade-fragmentation
-
Herein, a novel methodology for radical cyanomethylation is described. The process is initiated by radical addition to the vinyl azide reagent 3-azido-2-methylbut-3-en-2-ol which triggers a cascade-fragmentation mechanism driven by the loss of dinitrogen and the stabilised 2-hydroxypropyl radical, ultimately effecting cyanomethylation. Cyanomethyl groups can be efficiently introduced into a range of substrates via trapping of α-carbonyl, heterobenzylic, alkyl, sulfonyl and aryl radicals, generated from a variety of functional groups under both photoredox catalysis and non-catalytic conditions. The value of this approach is exemplified by the late-stage cyanomethylation of pharmaceuticals.
- Donald, James R.,Berrell, Sophie L.
-
p. 5832 - 5836
(2019/06/17)
-
- Ag2CO3-mediated direct functionalization of alkyl nitriles: Facile synthesis of γ-ketonitriles through nitrile alkylation of enol acetates
-
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
-
p. 1408 - 1412
(2019/05/06)
-
- Copper-Catalyzed Decarboxylative Oxyalkylation of Alkynyl Carboxylic Acids: Synthesis of ?-Diketones and ?-Ketonitriles
-
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
-
supporting information
p. 2227 - 2230
(2019/03/26)
-
- Development of a Flow Photochemical Aerobic Oxidation of Benzylic C-H Bonds
-
A continuous mesofluidic process has been developed for benzylic C-H oxidation with moderate to good yields using a photocatalyst (riboflavin tetraacetate, RFT) activated by a UV lamp and an iron additive [Fe(ClO4)2] via incorporation of singlet oxygen (1O2) for the direct formation of oxidized C=O or CH-OH compounds.
- Lesieur, Mathieu,Genicot, Christophe,Pasau, Patrick
-
supporting information
p. 1987 - 1990
(2018/04/16)
-
- Nickel-Catalyzed Cyanation of Unactivated Alkyl Chlorides or Bromides with Zn(CN)2
-
A nickel-catalyzed cyanation of unactivated secondary alkyl chlorides or bromides using less toxic Zn(CN)2 as the cyanide source has been developed. The reaction features the use of air-stable and inexpensive NiCl2·6H2O or Ni(acac)2 as the precatalysts and offers an efficient synthesis of a broad range of alkyl nitriles. Cyanation of primary alkyl chlorides or bromides was also achieved by reaction with Zn(CN)2 in the presence of n-Bu4NCl without the need of nickel catalyst.
- Xia, Aiyou,Xie, Xin,Chen, Haoyi,Zhao, Jidong,Zhang, Chunli,Liu, Yuanhong
-
supporting information
p. 7735 - 7739
(2019/01/03)
-
- Photoinduced C—C Bond Cleavage and Oxidation of Cycloketoxime Esters
-
A novel structural reorganization of cycloketoxime esters beyond the traditional Beckmann rearrangement process has been established to build cyano-containing ketones in the presence of photocatalyst. This novel transformation is remarkable with selective C—C bond cleavage and an oxidation process enabled by DMSO used as the solvent, oxidant, and oxygen source avoiding acid, base and toxic cyanide salts as the cyano source. Further applications in late-stage modification of complex and chiral molecules have also been reported.
- Zhao, Binlin,Tan, Hui,Chen, Cheng,Jiao, Ning,Shi, Zhuangzhi
-
p. 995 - 999
(2018/09/25)
-
- Light-Driven Vitamin B12-Catalysed Generation of Acyl Radicals from 2-S-Pyridyl Thioesters
-
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
-
supporting information
p. 3560 - 3565
(2017/10/24)
-
- Chemoselective Access to γ-Ketoesters with Stereogenic Quaternary α-Center or γ-Keto Nitriles by Aerobic Reaction of α-Cyanoesters and Styrenes
-
Chemoselective access to either γ-ketoesters with a quaternary all-carbon α-stereogenic center or γ-keto nitriles is described by copper-catalyzed aerobic reaction of styrenes with α-cyanoesters. Formal oxo-enolation or oxo-cyanomethylation of styrenes is achieved via a sequence of addition of enolate (or cyanomethyl) radical to olefin and oxidation of the resulting radical adduct. This method starts from abundant and cheap feedstock under aerobic conditions, without any prefunctionalization or the production of stoichiometric metal salts waste, making it very attractive for practical use.
- Zhang, Song-Lin,Wang, Xian-Jin,Yu, Ze-Long
-
supporting information
p. 3139 - 3142
(2017/06/23)
-
- Unactivated C(sp3)-H Bond Functionalization of Alkyl Nitriles with Vinylarenes and Mechanistic Studies
-
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
-
supporting information
p. 5986 - 5989
(2016/12/09)
-
- Synthesis method of 4-oxo-4-phenyl nitrile compound
-
The invention relates to a synthesis method of a 4-oxo-4-phenyl nitrile compound shown in a formula (III). The method comprises the following steps: reacting a compound in a formula (I) and a compound in a formula (II) in a solvent in presence of a catalyst, a ligand and an acid, and carrying out post-treatment after reaction is ended to obtain the compound in the formula (III) as shown in the specification, wherein R is H, halogen, C1-C6 alkyl or C1-C6 alkoxy; and X is an alkali metal element. According to the method, through selection of a unique reaction system formed by the special catalyst, ligand, acid and solvent, the 4-oxo-4-phenyl nitrile compound can be obtained at good yield; and the synthesis method has a good application prospect and industrial production potential in the field of organic chemical synthesis.
- -
-
Paragraph 0038; 0039; 0040; 0041; 0042; 0043
(2016/10/09)
-
- Synthetic method of symmetrically-substituted pyrrole compound
-
The invention relates to a synthetic method of a symmetrically-substituted pyrrole compound as shown in the formula (III). The method comprises the following steps: in a solvent and in the existence of a catalyst, a ligand, an acid compound and an ammonium source compound, performing the reaction of a compound as shown in the formula (I) and a compound as shown in the formula (II), and performing post-treatment after the reaction is ended, thereby obtaining a compound as shown in the formula (III) in the specification, wherein R is H, halogen, alkyl of C1 to C6 or alkoxy of C1 to C6; and X is an alkali metal element. According to the method, by virtue of the comprehensive selection and synergism of the specific catalyst, the ligand, the acid compound, the ammonium source compound and the solvent, the symmetrically-substituted pyrrole compound is obtained in high yield, and the application prospect and the industrialized production potential are good in the field of organic chemical synthesis.
- -
-
Paragraph 0064; 0065; 0066; 0067; 0068; 0069
(2016/10/17)
-
- Synthesis method of symmetric butanedione compounds
-
The invention relates to a synthesis method of symmetric butanedione compounds disclosed as Formula (III). The method comprises the following steps: in a solvent, carrying out reaction on compounds disclosed as Formula (I) and compounds disclosed as Formula (II) in the presence of a catalyst, a ligand and an acidic compound; and after the reaction finishes, carrying out after-treatment, thereby obtaining the compounds disclosed as Formula (III), wherein X is an alkali metal element. Under the combined selection and synergic actions of the specific catalyst, ligand, acidic compound and solvent, the method can overcome the defect of overlow yield of butanedione compounds in the prior art, can obtain the target products at high yield, and has favorable application prospects and industrial production potential in the field of organic chemical synthesis.
- -
-
Paragraph 0064-0067
(2017/02/28)
-
- Synthesis method of asymmetric diaryl substituted butanedione compounds
-
The invention relates to a synthesis method of asymmetric diaryl substituted butanedione compounds disclosed as Formula (III). The method comprises the following steps: in a solvent, carrying out reaction on compounds disclosed as Formula (I) and compounds disclosed as Formula (II) in the presence of a catalyst, a ligand and an acidic compound; and after the reaction finishes, carrying out after-treatment, thereby obtaining the compounds disclosed as Formula (III), wherein R is halogen, C1-C6 alkyl or C1-C6 alkoxy, and X is an alkali metal element. Under the combined selection and synergic actions of the specific catalyst, ligand, acidic compound and solvent, the method can obtain the asymmetric diaryl substituted butanedione compounds at high yield, and has favorable application prospects and industrial production potential in the field of organic chemical synthesis. Besides, the invention also relates to a synthesis method of the raw material compounds disclosed as Formula (I) and researches the optimal synthesis conditions and technical characteristics.
- -
-
Paragraph 0067-0070
(2017/04/03)
-
- Decarboxylative 1,4-Addition of α-Oxocarboxylic Acids with Michael Acceptors Enabled by Photoredox Catalysis
-
Enabled by iridium photoredox catalysis, 2-oxo-2-(hetero)arylacetic acids were decarboxylatively added to various Michael acceptors including α,β-unsaturated ester, ketone, amide, aldehyde, nitrile, and sulfone at room temperature. The reaction presents a new type of acyl Michael addition using stable and easily accessible carboxylic acid to formally generate acyl anion through photoredox-catalyzed radical decarboxylation.
- Wang, Guang-Zu,Shang, Rui,Cheng, Wan-Min,Fu, Yao
-
supporting information
p. 4830 - 4833
(2015/10/12)
-
- Discovery of phenoxybutanoic acid derivatives as potent endothelin antagonists with antihypertensive activity
-
A series of phenoxybutanoic acid derivatives were synthesized and tested for their antagonistic activity on the contraction of the rat thoracic aortic ring induced by endothelin-1. Preliminary screening results showed that 6e and 6g with benzoheterocycles demonstrated significant antagonistic activities when compared to the reference compound BQ123. The results from additional assays for the binding affinity and selectivity for endothelin receptors showed that 6e was a selective ETA antagonist with a nanomolar IC50. Moreover, 6e was effective in relieving hypoxia-induced pulmonary arterial hypertension and right ventricular weight ratio. Therefore, 6e may have potential for further development as a therapeutic agent for the treatment of cardiovascular diseases.
- Cai, Jin,Liu, Ligang,Hong, Kwon Ho,Wang, Peng,Li, Lushen,Cao, Meng,Sun, Chunlong,Wu, Xiaoqing,Zong, Xi,Chen, Junqing,Ji, Min
-
p. 657 - 667
(2015/02/19)
-
- Benzoin condensation and stetter reaction catalysed by N,N-dimethylbenzimidazolium iodide in [Bmim][OH]
-
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
-
p. 933 - 939
(2015/02/19)
-
- Unified oxidation protocol for the synthesis of carbonyl compounds using a manganese catalyst
-
We have developed a unified protocol for the oxidation of ethers, benzylic compounds, and alcohols to carbonyl compounds. The protocol uses catalytic amounts of manganese(II) chloride tetrahydrate and tri(t-butyl)-2,2':6',2Prime;- terpyridine in combination with a stoichiometric amount of either m-chloroperbenzoic acid (MCPBA) or potassium hydrogen peroxysulfate (KHSO 5). A reagent system consisting of the Mn catalyst and MCPBA permitted the chemoselective sp3 C-H oxidation of alkyl ethers and benzylic compounds to generate the corresponding ketones. Alternatively, the water-soluble inorganic salt KHSO5 in combination with the Mn catalyst was used to oxidize alcohols to ketones or carboxylic acids. Importantly, the Mn catalyst/KHSO5 system eliminates technical difficulties associated with the isolation of carboxylic acid products. All the oxidations presented in this feature article proceed at sup-ambient temperature in an aerobic atmosphere, and can therefore be used in practical syntheses of complex organic molecules. Georg Thieme Verlag Stuttgart · New York.
- Kamijo, Shin,Amaoka, Yuuki,Inoue, Masayuki
-
experimental part
p. 2475 - 2489
(2010/09/06)
-
- Benzylic carbon oxidation by an in situ formed o-iodoxybenzoic acid (IBX) derivative
-
Benzylic C-H bonds are selectively oxidized to the corresponding carbonyl functionalities using catalytic quantities of 2-iodobenzoic acid (2IBAcid) and Oxone. The reported procedure tolerates different functional groups and operates under mild conditions. A radical mechanism is proposed for the transformation and evidence supporting the proposed mechanism is also presented. Georg Thieme Verlag Stuttgart.
- Ojha, Lawanya R.,Kudugunti, Shashi,Maddukuri, Padma P.,Kommareddy, Amitha,Gunna, Meena R.,Dokuparthi, Praveen,Gottam, Hima B.,Botha, Kiran K.,Parapati, Divya R.,Vinod, Thottumkara K.
-
scheme or table
p. 117 - 121
(2009/05/30)
-
- A Pd(II)-catalyzed ring-expansion reaction of cyclic 2-azidoalcohol derivatives: Synthesis of azaheterocycles
-
(Chemical Equation Presented) A Pd(II)-catalyzed ring expansion-reaction of cyclic 2-azidoalcohol derivatives was found to proceed via an unprecedented C-C bond cleavage-C-N bond formation sequence, providing substituted azaheterocycles.
- Chiba, Shunsuke,Xu, Yan-Jun,Wang, Yi-Feng
-
supporting information; experimental part
p. 12886 - 12887
(2009/12/06)
-
- MITOTIC KINESIN INHIBITORS AND METHODS OF USE THEREOF
-
This invention relates to inhibitors of mitotic kinesins, particularly KSP, and methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing the inhibitors and pharmaceutical compositions in the treatment of various disorders.
- -
-
Page/Page column 43-44
(2008/06/13)
-
- A new manifold for the Morita reaction: Diene synthesis from simple aldehydes and acrylates/acrylonitrile mediated by phosphines
-
Dienes have been formed with good stereoselectivity and in good yield from simple aldehydes and acrylates/acrylonitrile in the presence of a phosphine and a Lewis acid through a modification of the Morita reaction. The Royal Society of Chemistry.
- Palmelund, Anders,Myers, Eddie L.,Tai, Lik Ren,Tisserand, Steve,Butts, Craig P.,Aggarwal, Varinder K.
-
p. 4128 - 4130
(2008/09/16)
-
- An effective new synthesis of 2-aminopyrrole-4-carboxylates
-
Efficient syntheses of 2-aminopyrroles are presented starting from β-dicarbonyl compounds, bromoacetonitrile, and amines. Alkylation of β-dicarbonyl compounds with bromoacetonitrile furnished α-cyanomethyl-β-dicarbonyl compounds. The condensation reaction of α-cyanomethyl-β-dicarbonyl compounds with amines catalyzed by p-TsOH affords the corresponding enamines in good yields. Base catalyzed cyclization via the addition of an amine moiety to the carbon-nitrogen triple bond of nitrile furnished 2-aminopyrroles in high yields.
- Demir, Ayhan S.,Emrullahoglu, Mustafa
-
p. 10482 - 10489
(2007/10/03)
-
- A new method for the synthesis of γ-oxobutyronitriles via addition of aroyl chlorides to acrylonitrile promoted by samarium metal in DMF
-
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
-
p. 163 - 164
(2007/10/03)
-
- Synthetic utility of stannyl enolates as radical alkylating agents
-
(Equation presented) The radical-initiated β-ketoalkylation of haloalkanes with tributylstannyl enolates is described. Stannyl enolates derived from aromatic ketones are reactive toward the homolytic β-ketoalkylation of simple haloalkanes as well as those activated by an electron-withdrawing group. The reactivity of stannyl enolates as radical alkylating agents can be utilized for an efficient three-component coupling reaction among stannyl enolates, haloalkanes, and electron-deficient alkenes.
- Miura, Katsukiyo,Fujisawa, Naoki,Saito, Hiroshi,Wang, Di,Hosomi, Akira
-
p. 2591 - 2594
(2007/10/03)
-
- Reaction of iron aminocarbene complexes with electronically deficient alkenes
-
Thermal reaction of iron aminocarbene complexes bearing aromatic substituent (CO)4Fe=C(Ar)N(CH3)2 with methyl acrylate, acrylonitrile and methyl vinyl ketone furnishes 1,4-dicarbonyl compounds - formal products of Michael
- Rotrekl, Ivan,Vyklicky, Libor,Dvorák, Dalimil
-
p. 329 - 333
(2007/10/03)
-
- Difluoroboroxymolybdenum fischer carbene complexes as precursors of acyl radicals: Dimerization and trapping with electron-deficient alkenes
-
Pentacarbonyl acyl molybdates 1 react with boron trifluoride to give difluoroboroxy Fischer carbene complexes 2, which undergo loss of the metal fragment at room temperature to form 1,2-diketones 3, 1,2-hydroxy ketones 4, or dimers 5 through a dimerization or decarbonylation-dimerization process of acyl radicals. Decomposition of 2 in the presence of electron-deficient alkenes 11 and 18 furnishes the two-, three-, and four-component coupling products 12, 13, 19, 20, and 21.
- Barluenga, Jose,Rodriguez, Felix,Fananas, Francisco J.
-
p. 1930 - 1937
(2007/10/03)
-
- Carbon-carbon bond cleavage of α-substituted benzoins by retro-benzoin condensation; A new method of synthesizing ketones
-
When α-benzylbenzoin (3a, α-benzyl-α-hydroxybenzyl phenyl ketone) was treated with potassium cyanide (1) in N,N-dimethylformamide at 80°C for 1h, the carbon-carbon bond was cleaved, resulting in the formation of deoxybenzoin (4a, benzyl phenyl ketone) and benzaldehyde (2a). This carbon- carbon bond cleavage proceeds through a retro-benzoin condensation mechanism. This method of synthesizing ketones was applied to several α-substituted benzoins (3), and the corresponding ketones (4) were formed in good yields. Further, we found that the cyanide ion-donating ability of tetrabutylammonium cyanide (6, Bu4NCN) is more effective than that of potassium cyanide (1, KCN). As expected from the chemical analogy between cyanide ion and azolium ylide, several azolium salts (7) can also be employed in the retro-benzoin condensation as catalysts. The benzoin derivatives 3 were synthesized in the following three ways; reaction of alkyl halide (9) with benzoin (5), Michael addition of benzoin (5) with acceptors (10), and Grignard reaction of benzils (8). Alkylation of the benzoins without isolation, followed by carbon-carbon bond cleavage, readily afforded the corresponding ketones (4).
- Miyashita, Akira,Suzuki, Yumiko,Okumura, Yoko,Iwamoto, Ken-Ichi,Higashino, Takeo
-
-
- Tert-Butyl Hypofluorite - An Electrophilic tert-Butoxylation Agent
-
tert-Butyl hypofluorite, t-BuOF, easily synthesized from Z-BuOH and F2, is a unique source of the novel electrophilic tert-butoxylium moiety t-BuO+. It was added to several benzylic double bonds to form vicinal fluoro-tert-butoxide derivatives. Not surprisingly, this bulky reagent is quite sensitive to steric hindrance. The process is electrophilic in nature, but since the reaction is relatively slow (20-60 min) formation of various radical species can take place, forming eventually several distinct byproducts. t-BuOF was also reacted with a number of enols, producing the corresponding α-tert-butoxy ketone derivatives in moderate to good yields. The best results were obtained with benzylic enol derivatives.
- Ben-David, Iris,Mishani, Eyal,Rozen, Shlomo
-
p. 4632 - 4635
(2007/10/03)
-
- Synthesis of ketones by retro-benzoin condensation catalyzed by potassium cyanide
-
The treatment of 2-benzyl-1,2-diphenyl-2-hydroxyethanone (3a, benzylbenzoin) with potassium cyanide in DMF gave deoxybenzoin (4a). The formation of deoxybenzoin (4a) proceeds through retro-benzoin condensation by catalytic action of cyanide ion. Similarly, retro-benzoin condensation applied to several substituted benzoins 3 resulted in the formation of the corresponding ketones 4 in excellent yields.
- Miyashita,Suzuki,Okumura,Higashino
-
p. 252 - 254
(2007/10/03)
-
- Facile synthesis of nitriles from primary nitro compounds via nitrolic acids and their esters
-
The reactions of alkane- and arylalkanenitrolic acids esters Bu3SnH in the presence of a catalytic amount of AIBN in refluxing benzene afforded the corresponding nitriles in excellent yields.
- Chang, Rae Kyu,Kim, Kyongtae
-
p. 7791 - 7794
(2007/10/03)
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- Generation of Acyl Radicals from 1-Oxidoalkylidenechromium(0) Complexes by Treatment with Bis(2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) and Their Reactions with Olefins
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Tetramethylammonium pentacarbonyl(1-oxidoalkylidene)chromium(0) complexes are oxidized with bis(2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) to generate acyl radicals which react electron-deficient olefins, giving intermolecular addition products.
- Sakurai, Hidehiro,Narasaka, Koichi
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p. 2017 - 2020
(2007/10/02)
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- 2-CYANOETHYLZINC IODIDE: A NEW REAGENT WITH REACTIVITY UMPOLUNG
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2-Cyanoethylzinc iodide 1 generated in over 90percent yield from 3-iodopropionitrile and zinc in THF can be transmetallated to the copper and titanium derivatives 3 and 4 which react in good yields, respectively, with acyl chlorides, enones, allylic halides and benzaldehyde.
- Yeh, Ming Chang P.,Knochel, Paul
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p. 2395 - 2396
(2007/10/02)
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- Metallic Nickel-Mediated Synthesis of Ketones by the Reaction of Benzylic, Allylic, Vinylic, and Pentafluorophenyl Halides with Acid Halides
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Metallic nickel was investigated as a convenient coupling reagent for the synthesis of ketones by the reaction of benzylic, allylic, vinylic, and pentafluorophenyl halides with acid halides at 85 deg C in glyme.A variety of benzylic ketones with functional groups including halogen, cyano, methoxycarbonyl, and hydroxycarbonyl groups were prepared in good yields by this method.The reaction was demonstrated to proceed via organonickel halide intermediates formed by the smooth oxidative addition of benzylic and acyl halides to metallic nickel, which were trapped with electron-deficient olefins. (?-Allyl)nickel halides, prepared in situ at 85 deg C from allylic halides and the nickel, also worked for the preparation of ketones.Vinylic and pentafluorophenyl halides but not alkyl halides reacted with acid halides to give the corresponding ketones in moderate yields.
- Inaba, Shin-ichi,Rieke, Reuben D.
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p. 1373 - 1381
(2007/10/02)
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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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