3355-28-0Relevant articles and documents
Stereocontrolled Construction of Condensed γ-Lactam Ring Systems by Cationic Cyclizations. Rearrangement of a γ-Lactam to a δ-Lactam
Marson, Charles M.,Grabowska, Urszula,Walsgrove, Timothy,Eggleston, Drake S.,Baures, Paul W.
, p. 284 - 290 (1994)
A new condensation of 3-alkenamides with benzaldehyde in acidic media, notably polyphosphoric acid, lead to γ-lactam rings with high regio- and stereocontrol.One such γ-lactam was shown to undergo a novel and stereocontrolled ring-expansion to a δ-lactam.
Construction of N-Heterocyclic Systems Containing a Fully Substituted Allylic Carbon by Palladium/Phosphine Catalysis
Ogiwara, Yohei,Suzuki, Yui,Sato, Kazuya,Sakai, Norio
, p. 6965 - 6969 (2018)
The unique cyclization of benzamide derivatives that contain an alkyne by a Pd(0)/dialkyl(biaryl)phosphine catalytic system is reported. The reaction efficiently provides a variety of six-membered N-heterocyclic compounds that contain a fully substituted carbon center without the need for a stoichiometric additive. Mechanistic studies suggest that this unprecedented cyclization starts with the cleavage of a propargylic C-O bond, and a 1,3-diene has been identified as a relevant intermediate.
Synthesis of Spirobicyclic Pyrazoles by Intramolecular Dipolar Cycloadditions/[1s, 5s] Sigmatropic Rearrangements
Dimirjian, Christine A.,Casti?eira Reis, Marta,Balmond, Edward I.,Turman, Nolan C.,Rodriguez, Elys P.,Di Maso, Michael J.,Fettinger, James C.,Tantillo, Dean J.,Shaw, Jared T.
supporting information, p. 7209 - 7212 (2019/10/02)
The formation of fused pyrazoles via intramolecular 1,3-dipolar cycloadditions of diazo intermediates with pendant alkynes is described. A subsequent thermal [1s, 5s] sigmatropic shift of these pyrazole systems resulted in a ring contraction, forming spirocyclic pyrazoles. The limitations of this rearrangement were explored by changing the substituents on the nonmigrating aromatic ring and by using substrates lacking an aromatic linkage to the propargyl group.
Cobalt-catalyzed versus uncatalyzed intramolecular Diels-Alder cycloadditions
Biletskyi, Bohdan,Tenaglia, Alphonse,Clavier, Hervé
supporting information, p. 103 - 107 (2017/12/28)
The intramolecular [4+2] cycloadditions of dienynes was investigated using cobalt-based catalysts. Substrates without substitution on alkyne moiety were found to react under thermal activation. The use of a cobalt salt as catalyst made reactions cleaner by limiting the formation of byproducts. Cycloadditions with dienynes possessing a substituent on the alkyne pattern occurred only in presence of a cobalt catalyst which displayed a moderate to good activity depending on the substrate patterns.
Synthesis of Carbolines via Palladium/Carboxylic Acid Joint Catalysis
Cera, Gianpiero,Lanzi, Matteo,Balestri, Davide,Della Ca, Nicola,Maggi, Raimondo,Bigi, Franca,Malacria, Max,Maestri, Giovanni
supporting information, p. 3220 - 3224 (2018/06/11)
The combination of a Pd(0) complex with benzoic acid converts propargylic tryptamines to the corresponding tetrahydro-β-carbolines. The method uses unprotected indoles and affords the desired products with ample functional group tolerance. Detailed modeling studies reveal a close synergy between the organic and metal catalysts, which enables sequential alkyne isomerization, indole C-H activation, and eventual C-C reductive elimination to afford the target heterocycles.
Gold-Catalyzed Regiodivergent [2 + 2 + 2]-Cycloadditions of Allenes with Triazines
Peng, Shiyong,Cao, Shengyu,Sun, Jiangtao
supporting information, p. 524 - 527 (2017/02/10)
Gold-catalyzed regiodivergent cycloadditions of functionalized allenes with 1,3,5-triazines, providing diverse N-heterocycles in moderate to excellent yields under mild reaction conditions, are reported. Importantly, different types of allenes exhibit distinct selectivity and reactivity for the reactions. Mechanistic investigations reveal that all of the cycloadditions proceed through a stepwise [2 + 2 + 2]-cycloaddition process.
Kinetics of the reaction of N,N-dimethylaniline with 1-bromoalk-2-ynes
Andreev,Ryzhakov,Sobolev
, p. 1486 - 1489 (2017/09/01)
Quaternization of N,N-dimethylaniline with propargyl bromide, 1-bromobut-2-yne, and 1-bromooct-2-yne were studied. It was shown that, with the lengthening chain of the substituent at the triple bond, the quaternization rate tends to increase.
Palladium-catalyzed cyclization of alkynoic acids to form vinyl dioxanones bearing a quaternary allylic carbon
Ogiwara, Yohei,Sato, Kazuya,Sakai, Norio
supporting information, p. 5296 - 5299 (2017/11/06)
A palladium-catalyzed intramolecular reaction of carboxylic acids and alkynes in a novel cyclization manner was developed. This unique cyclization efficiently provided a wide range of complex ring systems-vinyl dioxanones bearing a quaternary allylic carbon. Mechanistic studies suggest an allenyl carboxylate as an intermediate.
A 1 - bromo - 2 - ethyl-acetylene production method (by machine translation)
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Paragraph 0014, (2017/06/13)
The invention relates to a 1 - bromo - 2 - ethyl-acetylene production method, including in the THF bromoethane with magnesium metal in the reaction to prepare the Grignard reagent, then to the Grignard reagent in the form after adding poly-formaldehyde reaction, format after the reaction separation and recovery 2 - ethyl-acetylene - 1 - ol; and will 2 - ethyl-acetylene - 1 - ol with phosphorus tribromide bromination reaction, bromination reaction after the end of the separation and recovery of 1 - bromo - 2 - ethyl-acetylene. In this invention the format adopted for the more common reaction currently in use, and does not need special production equipment, the reaction condition is comparatively mild, in industrialized production process is more stable, with a low risk. The phosphorus tribromide to 2 - ethyl-acetylene - 1 - ol performing the bromination, the utilization rate of high, produce by-products phosphoric acid and in pyridine and easy processing. (by machine translation)
Bioorthogonal Enzymatic Activation of Caged Compounds
Ritter, Cornelia,Nett, Nathalie,Acevedo-Rocha, Carlos G.,Lonsdale, Richard,Kr?ling, Katja,Dempwolff, Felix,Hoebenreich, Sabrina,Graumann, Peter L.,Reetz, Manfred T.,Meggers, Eric
supporting information, p. 13440 - 13443 (2015/11/09)
Engineered cytochrome P450 monooxygenase variants are reported as highly active and selective catalysts for the bioorthogonal uncaging of propargylic and benzylic ether protected substrates, including uncaging in living E. coli. observed selectivity is supported by induced-fit docking and molecular dynamics simulations. This proof-of-principle study points towards the utility of bioorthogonal enzyme/protecting group pairs for applications in the life sciences.
