- Intermolecular [5 + 1]-Cycloaddition between Vinyl Diazo Compounds and tert-Butyl Nitrite to 1,2,3-Triazine 1-Oxides and Their Further Transformation to Isoxazoles
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1,2,3-Triazine 1-oxides are formed by nitrosyl addition from tert-butyl nitrite to the vinylogous position of vinyl diazo compounds. This transformation, which is a formal intermolecular [5 + 1] cycloaddition, occurs under mild conditions, with high funct
- De Angelis, Luca,Zheng, Haifeng,Perz, Matthew T.,Arman, Hadi,Doyle, Michael P.
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supporting information
p. 6542 - 6546
(2021/08/30)
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- Visible-light-driven radical 1,3-addition of selenosulfonates to vinyldiazo compounds
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Herein, we report a visible-light-driven radical 1,3-selenosulfonylation of vinyldiazo compounds with selenosulfonates, providing various γ-seleno allylic sulfones in good yields. This photochemical reaction was carried out at room temperature in an open flask using ethyl acetate as the solvent without any photocatalysts or additives. The control experiments corroborated that the 1,3-addition proceeded via a radical-chain propagation process. The synthetic applications of the resulting products were demonstrated by deselenization, reduction, bromination and allylation.
- Li, Weiyu,Zhou, Lei
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supporting information
p. 6652 - 6658
(2021/09/10)
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- Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow
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Ethyl diazoacetate (EDA) is one of the most prominent diazo reagents. It is frequently used in metal–carbene-type reactions. However, EDA can also be used as a nucleophile under base catalysis. Whilst the addition of EDA to aldehydes can be performed using organic bases, the addition of EDA to other carbonyl electrophiles requires the use of organometallics such as lithium diisopropylamide (LDA). The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at low temperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields.
- Müller, Simon T. R.,Hokamp, Tobias,Ehrmann, Svenja,Hellier, Paul,Wirth, Thomas
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supporting information
p. 11940 - 11942
(2016/08/16)
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- Gold-catalyzed formal [3 + 3] and [4 + 2] cycloaddition reactions of nitrosobenzenes with alkenylgold carbenoids
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We report two new formal cycloaddition reactions between nitrosobenzenes and alkenylgold carbenoids. We obtained quinoline oxides 3 in satisfactory yields from the gold-catalyzed [3 + 3]-cycloadditions between nitrosobenzenes and alkenyldiazo esters 1. For propargyl esters 5, its resulting gold carbenes react with nitrosobenzene to give alkenylimine 8, followed by a [4 + 2]-cycloaddition with nitrosobenzene.
- Pagar, Vinayak Vishnu,Jadhav, Appaso Mahadev,Liu, Rai-Shung
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supporting information; experimental part
p. 20728 - 20731
(2012/02/13)
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- Pd-catalyzed coupling of β-hydroxy α-diazocarbonyl compounds with aryl iodides: A migratory insertion/β-hydroxy elimination sequence
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The coupling of β-hydroxy α-diazocarbonyl compounds with aryl halides is described, which proceeds through a Pd-catalyzed migratory insertion/β-OH elimination sequence. This reaction provides a new route to the synthesis of tetrasubstituted olefins.
- Zhou, Lei,Liu, Yizhou,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 3622 - 3624
(2011/05/02)
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- Highly selective catalyst-directed pathways to dihydropyrroles from vinyldiazoacetates and imines
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Copper-catalyzed reactions of vinyldiazoacetates with imines occur via a pathway in which the activated imine undergoes electrophilic addition to the vinyldiazo compound, whereas reactions catalyzed by rhodium(II) proceed through a metal carbene to an int
- Doyle, Michael P.,Yan, Ming,Hu, Wenhao,Gronenberg, Luisa S.
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p. 4692 - 4693
(2007/10/03)
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- Reaction of Carbonyl Compounds with Ethyl Lithiodiazoacetate. Studies Dealing with the Rhodium(II)-Catalyzed Behavior of the Resulting Adducts
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The carbenoid intermediate derived by treating ethyl 2-diazo-4-phthalimidobutyrate with rhodium(II) octanoate undergoes transannular cyclization onto the adjacent imido carbonyl group.The resulting cyclic carbonyl ylide diploe was trapped with several dipolarophiles.In an attempt to prepare related substrates for cyclization studies, the reaction of ethyl lithiodiazoacetate with various aldehydes and ketones was studied.Treatment of the α-diazo-β-hydroxy ester derived from acetone or cyclopentanone with rhodium(II) octanoate gave rise to a β-keto ester.The exclusive phenyl shift encountered with acetophenone is in keeping with migration to an electron-deficient center.The reaction works well with acrolein, leading to high yields of 3-oxo-4-pentenoate.The 1,2-hydrogen shift pathway was found to proceed much faster than intramolecular cyclopropanation.Dehydration of the α-diazo-β-hydroxy esters generates vinyl diazo esters, which readily cyclize to 1H-pyrazoles on thermolysis.
- Padwa, Albert,Kulkarni, Yashwant S.,Zhang, Zhijia
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p. 4144 - 4153
(2007/10/02)
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