- NovelN-transfer reagent for converting α-amino acid derivatives to α-diazo compounds
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A novel universalN-transfer reagent for direct and effective transformation of α-amino ketones, acetamides, and esters to the corresponding α-diazo products under mild basic conditions has been developed. This one-step synthetic approach not only allows for generation of α-substituted-α-diazo carbonyl compounds from α-amino acid derivatives but also permits preparation of α-diazo dipeptides fromN-terminal dipeptides (32 examples, up to 91%).
- Lu, Guan-Han,Huang, Tzu-Chia,Hsueh, Hsiao-Chin,Yang, Shin-Cherng,Cho, Ting-Wei,Chou, Ho-Hsuan
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supporting information
p. 4839 - 4842
(2021/05/25)
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- N-transfer reagent and method for preparing the same and its application
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Provided are a novel N-transfer reagent and a method for preparing the same and its application. The N-transfer reagent is represented by the following Formula (I): The various novel N-transfer reagents of the present invention can be quickly prepared by employing different nitrobenzene precursors. The N-transfer reagents can directly convert a variety of amino compounds into diazo compounds under mild conditions. Particularly, the N-transfer reagents can facilitate the synthesis of the diazo compounds. The application of synthesizing diazo compounds of the present invention can greatly decrease the difficulty in operation, increase the safety during experiments, reduce the cost of production and the environmental pollution, and enhance the industrial value of diazo compounds.
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Page/Page column 26-29; 59-60; 69-70
(2021/06/25)
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- Practical Application of the Aqueous 'Sulfonyl-Azide-Free' (SAFE) Diazo Transfer Protocol to Less α-C-H Acidic Ketones and Esters
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The earlier described 'sulfonyl-Azide-free' ('SAFE') protocol for diazo transfer to CH-Acidic 1,3-dicarbonyl compounds (and their similarly activated congeners) has been extended to the less reactive monocarbonyl substrates, which previously required a se
- Dar'In, Dmitry,Kantin, Grigory,Krasavin, Mikhail
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p. 4284 - 4290
(2019/11/14)
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- Metal-Free Insertion Reactions of Diazo Carbonyls to Azlactones
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Insertion reactions of diazo carbonyls to azlactones in basic conditions have been performed. The developed method allows the preparation of a wide range of oxazole derivatives in yields ranging from 74 to 98%. Different substituents on both azlactone rings and diazo carbonyls do not compromise the methodology, even those containing stereogenic centers. Isotopic labeling experiments revealed the mechanism may proceed through a rare diazo carbonyl activation by an ammonium salt derivative.
- De Mello, Amanda C.,Momo, Patrícia B.,Burtoloso, Antonio C. B.,Amarante, Giovanni W.
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p. 11399 - 11406
(2018/09/12)
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- Site-Selective Conversion of Azido Groups at Carbonyl α-Positions to Diazo Groups in Diazido and Triazido Compounds
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This paper reports on the selective conversion of alkyl azido groups at the carbonyl α-position to diazo compounds. Through β-elimination of dinitrogen, followed by hydrazone formation/decomposition, α-azidocarbonyl moieties were transformed into α-diazo carbonyl groups in one step. As these reaction conditions do not involve aryl or general alkyl azides, site-selective conversions of di- and triazides were achieved. Through this method, the successive site-selective conjugation of the triazido molecule with three different components is demonstrated.
- Yokoi, Taiki,Tanimoto, Hiroki,Ueda, Tomomi,Morimoto, Tsumoru,Kakiuchi, Kiyomi
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p. 12103 - 12121
(2018/10/09)
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- Phosphoric Acid Catalyzed [4 + 1]-Cycloannulation Reaction of ortho-Quinone Methides and Diazoketones: Catalytic, Enantioselective Access toward cis-2,3-Dihydrobenzofurans
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A highly straightforward route to enantiomerically highly enriched cis-2,3-dihydrobenzofurans has been achieved via addition of α-diazocarbonyl compounds to in situ generated o-QMs catalyzed by a chiral Br?nsted acid. This catalytic strategy provides a direct access to 2,3-dihydrobenzofurans in high yields and with up to 91:9 dr and 99:1 er at ambient temperature. Moreover, a unique phenonium-type rearrangement accounts for product formation with an inverted 2,3-substitution pattern.
- Suneja, Arun,Schneider, Christoph
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supporting information
p. 7576 - 7580
(2019/01/03)
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- Photoinduced Multicomponent Synthesis of α-Silyloxy Acrylamides, an Unexplored Class of Silyl Enol Ethers
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The photoinduced, multicomponent reaction of α-diazoketones, silanols, and isocyanides affords α-silyloxy acrylamides, formally derived from α-keto amides. The presence of a secondary amido group makes classic preparative methods for silyl enol ethers unfeasible in this case, while the mild conditions required by this photochemical approach allow their synthesis in good yields; moreover, the general structure can be easily modified by varying each component of the multicomponent reaction. Fine-tuning of the reaction conditions (i.e., solvents, radiation, additives) can be exploited to obtain complete Z selectivity. The reactivity of this overlooked class of silyl enol ethers has been investigated, and features that could pave the way to new applications have been found.
- Ibba, Francesco,Capurro, Pietro,Garbarino, Silvia,Anselmo, Manuel,Moni, Lisa,Basso, Andrea
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supporting information
p. 1098 - 1101
(2018/02/23)
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- Tandem Synthesis of α-Diazoketones from 1,3-Diketones
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A highly efficient synthesis of α-diazoketone was achieved by simply stirring the mixture of 1,3-diketone, TsN3, and MeNH2 in EtOH. It was a tandem reaction including a novel primary amine-catalyzed Regitz diazo transfer of 1,3-diket
- Zhang, Jianlan,Chen, Wenwen,Huang, Dayun,Zeng, Xiaobao,Wang, Xinyan,Hu, Yuefei
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p. 9171 - 9174
(2017/09/11)
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- A Sequential Route to Cyclopentenes from 1,6-Enynes and Diazo Ketones through Gold and Rhodium Catalysis
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This work reports the construction of cyclopentene cores from 1,6-enynes and aryl diazo ketones through two new reaction sequences involving initial gold-catalyzed cyclization of 1,6-enynes with diazo species, followed by rhodium-catalyzed skeletal rearrangement of the resulting 3-cyclopropyl-2-en-1-ones. In most instances the rhodium-catalyzed reactions afforded cyclopentene derivatives whereas several n-alkyl- or ortho-substituted phenyl ketones delivered seven-membered oxacycles. A plausible mechanism provides rationales for these two distinct products. (Figure presented.).
- Kale, Balaji S.,Lee, Hsin-Fu,Liu, Rai-Shung
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supporting information
p. 402 - 409
(2017/02/10)
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- Facile access to 2,2-disubstituted indolin-3-ones: Via a cascade Fischer indolization/Claisen rearrangement reaction
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An efficient approach for the synthesis of 2,2-disubstituted indolin-3-ones is described. From readily accessible aryl hydrazines and allyloxyketones, 2,2-disubstituted indolin-3-ones could be obtained in good to excellent yields under mild reaction condi
- Xia, Zilei,Hu, Jiadong,Gao, Yu-Qi,Yao, Qizheng,Xie, Weiqing
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supporting information
p. 7485 - 7488
(2017/07/12)
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- Radical Cation Cyclopropanations via Chromium Photooxidative Catalysis
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The chromium photocatalyzed cyclopropanation of diazo reagents with electron-rich alkenes is described. The transformation occurs under mild conditions and features specific distinctions from traditional diazo-based cyclopropanations (e.g., avoiding β-hydride elimination, chemoselectivity considerations, etc.). The reaction appears to work most effectively using chromium catalysis, and a number of decorated cyclopropanes can be accessed in generally good yields.
- Sarabia, Francisco J.,Ferreira, Eric M.
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supporting information
p. 2865 - 2868
(2017/06/07)
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- Gold-Catalyzed [2,3]-Sigmatropic Rearrangement: Reaction of Aryl Allyl Alcohols with Diazo Compounds
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A gold-catalyzed [2,3]-sigmatropic rearrangement reaction has been developed. The intermolecular rearrangement occurs between in situ generated donor-acceptor gold-carbenes and cinnamyl alcohols via tandem oxonium ylide formation. The desired rearranged product has been accomplished selectively over more conventional O-H insertion, cyclopropanation, cycloaddition, and C-H functionalization products under mild, open-air conditions. The scope of the work has been illustrated by synthesizing a new class of substrates that can be used for constructing complex molecular targets.
- Rao, Santhosh,Prabhu, Kandikere Ramaiah
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supporting information
p. 846 - 849
(2017/02/26)
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- One-pot synthesis of trans-β-lactams from ferrocenylketene generated by thermal Wolff rearrangement
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A series of β-lactams containing the ferrocene moiety were synthesized through the Staudinger reaction between ferrocenylketene generated by the thermal Wolff rearrangement of the corresponding diazo ketone and various imines. The stereochemical outcome h
- Liu, Mingshun,Wang, Jian’an,Yuan, Xiaoxi,Jiang, Rong,Fu, Nanyan
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supporting information
p. 2369 - 2377
(2017/12/12)
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- One-pot synthesis of polyfunctional pyrazoles: An easy access to α-diazoketones from arylglyoxal monohydrates and tosylhydrazine
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A new and efficient method for the generation of α-diazoketones has been developed from arylglyoxal monohydrates and tosylhydrazine at room temperature. 1,3-Dipolar cycloaddition reactions were used to constructing polyfunctional pyrazole derivatives by the reaction of generated α-diazoketones in situ with electron-deficient alkenes, quinones and coumarins in one pot. The one-dimensional molecular packing of 1H-benzo[f]indazole-4,9-dione derivatives along the c direction demonstrated a helical chain formation via N-H?O hydrogen-bonding.
- Shu, Wen-Ming,Ma, Jun-Rui,Zheng, Kai-Lu,Sun, Hui-Ying,Wang, Mei,Yang, Yan,Wu, An-Xin
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p. 9321 - 9329
(2015/03/05)
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- TAK1 KINASE INHIBITORS, COMPOSITIONS, AND USED RELATED THERETO
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The disclosure relates to TAK1 inhibitors, compositions, and uses related thereto. In certain embodiments, the disclosure relates to compounds of formula (I), pharmaceutical compositions having a compound of formula (I), and methods of treating or prevent
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Page/Page column 52; 53
(2013/03/26)
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- Amination of phenylketene revisit. Substituent effect on reactivity
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The asymmetric stretching frequencies of the ketene group of the m,p-substituted phenylketenes were found to be correlated with σ The substituent effects for the second-order rate constants of phenylketenes with various amines were not correlated linearly
- Badal, Md. Mizanur Rahman,Zhang, Min,Kobayashi, Shinjiro,Mishima, Masaaki
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p. 856 - 863
(2013/08/15)
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- Rhodium(II)-catalyzed cross-coupling of diazo compounds
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Nothing left to chance: A convenient protocol for selective cross-coupling of diazo compounds for the convergent synthesis of alkenes was developed (see scheme; EDG=aryl, heteroaryl, vinyl; R=O-alkyl, aryl). The selectivity control elements were identifie
- Hansen, Joorn H.,Parr, Brendan T.,Pelphrey, Philip,Jin, Quihui,Autschbach, Jochen,Davies, Huw M. L.
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supporting information; experimental part
p. 2544 - 2548
(2011/04/27)
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- Improved arndt-eistert synthesis of α-diazoketones requiring minimal diazomethane in the presence of calcium oxide as acid scavenger
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A practical methodology to obtain α-diazoketones through an improved Arndt-Eistert synthesis is described. The method allows the efficient transformation of acid halides using a stoichiometric amount of diazomethane in the presence of calcium oxide, witho
- Pace, Vittorio,Verniest, Guido,Sinisterra, Josep-Vicent,Alcantara, Andres R.,De Kimpe, Norbert
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supporting information; experimental part
p. 5760 - 5763
(2010/10/03)
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- A cascade approach to pyridines from 2-Azido-2,4-dienoates and α-diazocarbonyl compounds
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A one-pot synthesis of substituted pyridines via a cascade reaction of 2-azido-2,4-dienoates with α-diazocarbonyl compounds and triphenylphosphine is reported. The process involves a Staudinger-Meyer reaction, a Wolff rearrangement, an aza-Wittig reaction, and an electrocyclic ring- closure. The procedure is general and efficient. The substrates are readily available.
- Chen, Zheng-Bo,Hong, Deng,Wang, Yan-Guang
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supporting information; experimental part
p. 903 - 905
(2009/06/20)
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- Aryl trialkylsilyl ketenes: Acid-catalyzed synthesis from 1-aryl-2-diazo-2-trialkylsilylethanones and their conversion into 3-silyl-1-silyloxyallenes
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Aryl-substituted α-silyl α-diazo ketones are readily transformed into aryl silyl ketenes in the presence of a catalytic amount of triflic acid. Thus, a convenient method to prepare these silyl ketenes becomes available, which combines two steps, silylation of an aryl diazomethyl ketone and acid-induced Wolff rearrangement of the formed α-silyl α-diazo ketone, in a one-pot procedure. It appears that the trialkyl-ammonium salt, which is formed in the silylation step, can also catalyze the Wolff rearrangement, but distinctly more slowly than the proton acid. The silyl ketenes react smoothly with α-silyl α-diazo ketones to form 3-silyl-1-silyloxyallenes in fairly good yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Bucher, Stefan M.,Brueckmann, Ralf,Maas, Gerhard
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body text
p. 4426 - 4433
(2009/05/07)
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- Formation of fulleroids as major products and application of solid state reaction in the functionalization of 60|fullerene by aromatic diazoketones
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The reactions of various aromatic diazoketones with [60]fullerene were investigated in solution (o-dichlorobenzene) or in the solid-state. Under all the conditions examined, the fulleroid with the methine proton located over a six-membered ring was obtain
- Nakamura, Yosuke,Inamura, Ken'ichi,Oomuro, Ryosuke,Laurenco, Richard,Tidwell, Thomas T.,Nishimura, Jun
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p. 3032 - 3038
(2007/10/03)
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- Aracyl triflates as derivatizing agents for biological betaines
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Several trifluoromethanesulfonates of general structure ArCOCH 2OTf were prepared and their suitability for use as derivatizing agents for the HPLC analysis of betaines was assessed. Four of them (Ar=2′-naphthyl, 2′-fluorenyl, 6′-methoxynaphtha
- Happer, D. Alan R.,Hayman, Colin M.,Storer, Malina K.,Lever, Michael
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p. 467 - 472
(2007/10/03)
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- Indium triflate: A mild and efficient Lewis acid catalyst for O-H insertion reactions of α-diazo ketones
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Facile O-H insertion reactions of α-diazo ketones with aliphatic/aromatic alcohols or benzenethiol have been developed in the presence of indium triflate as a catalyst. These reactions provided good yields of α-alkoxy ketones. A comparative study with other Lewis acids establishes the reactivity of indium triflate in O-H insertion reactions of α-diazo ketones.
- Muthusamy, Sengodagounder,Babu, Srinivasarao Arulananda,Gunanathan, Chidambaram
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p. 3133 - 3136
(2007/10/03)
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- A new and efficient route toward the preparation of diazo ketones using cyanuric chloride and diazomethane
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A new method for the preparation of diazo ketones has been developed. 2,4,6-Trichloro-1,3,5-triazine (cyanuric chloride) has been found to be an excellent coupling reagent allowing for the efficient transfer of diazomethane to a carboxylic acid. Preparation of diazo ketones using carboxylic acids and triazine reagents is considerably more convenient than classical diazo transfer protocols because water does not have to be stringently removed and the entire procedure can be carried out in one-pot. Electron deficient and neutral aryl carboxylic acids were found to give better results than electron rich or aliphatic carboxylic acids. (C) 2000 Elsevier Science Ltd.
- Forbes,Barrett,Lewis,Smith
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p. 9943 - 9947
(2007/10/03)
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- Spectroscopy and absolute reactivity of ketenes in acetonitrile studied by laser flash photolysis with time-resolved infrared detection
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Laser flash photolysis with time-resolved infrared detection of transients (LFP-TRIR) has been used to study the IR spectroscopy and reactivity of a number of substituted ketenes, prepared by the 308-nm photolysis of α-diazocarbonyl precursors in acetonitrile solution at room temperature. The correlation of the experimental ketene asymmetric stretching frequency to the Swain-Lupton field (F) and resonance (R) effect substituent parameters was unsatisfactory, whereas the correlation to the inductive substituent parameter (σ1) of Charton gave excellent results. This suggests that the asymmetric stretching frequency of substituted ketenes depends mainly on the inductive (i.e., field) effect of the substituents. The mechanism and kinetics of the reactions of these ketenes with various amines in acetonitrile were also studied. An intermediate species identified as either zwitterionic ylide or amide enol formed in the nucleophilic addition of the secondary amine to the C(α) of the ketene is observed by TRIR. The decay of this species is assisted by the amine and is concomitant with the formation of an amide, the final product of the reaction. Our kinetic data on ketene amine reactions show a general trend, indicating a much higher reactivity (ca. 3 orders of magnitude difference in the corresponding rate constants) of secondary amines compared with that of tertiary amines. Secondary diethylamine shows reactivity similar to those observed for primary amines, while secondary piperidine seems to be, in general, somewhat more reactive. The observed trend is rationalized in terms of the steric effects exerted by both amine and ketene substituents. Our data on para-substituted phenyl ketenes provide support for the negative charge development on the ketene moiety in the transition state, with electron-withdrawing substituents accelerating and electron-releasing substituents slowing down the addition reaction.
- Wagner, Brian D.,Arnold, Bradley R.,Brown, Gerald S.,Lusztyk, Janusz
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p. 1827 - 1834
(2007/10/03)
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- The synthesis of α-fluoroketones by 1,4-additions of mono-fluorinated enamines to Michael acceptors
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Stork enamine reactions are explored with mono-fluorinated enamines derived from α-fluoroacetophenones and pyrrolidine. The resulting enamines react under mild conditions with Michael acceptors (acrylonitrile, methyl acrylate, methyl methacrylate, methyl vinyl ketone and cyclohexenone) to generate a variety of substituted α-fluoroketones.
- Bridge, Colin F.,O'Hagan, David
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- Aroyldiazomethanes by mild acyl cleavage of diaroyldiazomethanes over Al2O3
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The synthesis of aroyldiazomethanes by the mild and rapid acyl cleavage of diaroyldiazomethanes on the surface of neutral alumina is reported.
- Korneev,Richter
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p. 1248 - 1250
(2007/10/02)
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- Diazoaldehyde Chemistry. Part 1. Transdiazotization of Acylacetaldehydes in Neutral-to-Acidic Medium. A Direct Approach to the Synthesis of α-Diazo-β-oxoaldehydes
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First ever non-deformylating transdiazotization of acylacetaldehydes was achieved: the reactions of 2-azido-1-ethylpyridinium tetrafluoroborate (4) with acylacetaldehydes 3 proceeded partially without deformylation to yield 16 new α-diazo-β-oxoaldehydes 1 along with diazomethyl ketones 2, especially in the presence of NaOAc (Scheme 1, Tables 1 and 2).The product distribution was substituent-dependent and could be correlated quantitatively.This new diazotization reaction appears as an alternative, direct, and more general method for the synthesis of these diazooxoaldehydes. α-Oxocycloalkanecarbaldehydes 5 gave only traces (if any) of α-diazocycloalkanones 7, and rearrangement products 6 were isolated (Scheme 2).Mechanisms of the reactions are discussed (Schemes 4 and 5).
- Sezer, Oezkan,Anac, Olcay
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p. 2323 - 2334
(2007/10/02)
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- α-Oxosulfones, 3. - Reactions of Acyclic α-Oxosulfones
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The course of reactions of acyclic α-oxosulfones with protic and aprotic nucleophiles is described.A far-reaching analogy to reactions of acyl halides is noticed.
- Schank, Kurt,Werner, Frank
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p. 1477 - 1481
(2007/10/02)
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