- A Method for the Preparation of β-Amino-α,β-unsaturated Carbonyl Compounds: Study of Solvent Effect and Mechanism
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An efficient method for the preparation of β-amino-α,β-unsaturated carbonyl compounds is demonstrated. Bench-stable sodium 3-oxo-enolates were prepared from carbonyl compounds, and reacted with amines in the presence of an acid and a desiccant. DFT studie
- R. S., Reyno,Sugunan, Akash,S., Ranganayakulu,Suresh, Cherumuttathu H.,Rajendar, Goreti
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supporting information
p. 1040 - 1045
(2020/02/15)
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- Relay Catalysis to Synthesize β-Substituted Enones: Organocatalytic Substitution of Vinylogous Esters and Amides with Organoboronates
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Organocatalysis was shown to facilitate conjugate additions to vinylogous esters and amides for the first time. Subsequent elimination of a β-alcohol or amine provided π-conjugated β-substituted enones. Remarkably, nucleophile addition to the electron-rich vinylogous substrates is more rapid than classical enones, forming monosubstituted products. A doubly organocatalytic (organic diol and methyl aniline) conjugate addition synthesized the products directly from alkynyl ketones. Both of these catalytic transformations are orthogonal to transition metal catalysis, allowing for good yields, easily accessible or commercially available reagents, high selectivity, reagent recovery and recyclability, facile scalability, and exceptional functional group tolerance.
- Sundstrom, Sasha,Nguyen, Thien S.,May, Jeremy A.
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supporting information
p. 1355 - 1359
(2020/02/13)
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- Scalable synthesis of highly reactive 1,3-diamino dienes from vinamidinium salts and their use in Diels-Alder reactions
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A practical and chromatography-free synthesis of vinamidinium salts and their use as diene precursors in Diels-Alder reactions is reported. Additionally, 1,3-dipyrrolidino-1,3-butadiene was shown to be significantly more reactive than Rawal's diene in a c
- Zhou, Sida,Sanchez-Larios, Eduardo,Gravel, Michel
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experimental part
p. 3576 - 3582
(2012/06/15)
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- Synthesis and reactions of haloazodienes. A new and general synthesis of substituted pyridazines
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The reaction of dihalohydrazones with Hunig's base gives 1-carbethoxy-3-phenyl-4-haloazodienes in-situ, which were found to combine with a variety of electron rich olefins to yield halo-substituted tetrahydropynidazines. These haloazodiene cyclizations are best characterized as inverse electron demand, 4 + 2 hetero Diels-Alder reactions that maintain a high degree of regio- and stereochemical control. The chloro-substituted tetrahydropyridazines that are formed give high yields of substituted pyridazines upon treatment with base. The sequence of a chloroazodiene cyclization to a tetrahydropyridazine followed by an aromatization constitutes a new and general synthesis of substituted pyridazines. In contrast to the haloazodiene cyclizations, the novel cyclization reactions of the in-situ generated 1-carbethoxy-3-phenyl-4,4-dichloroazodiene were found to give N-aminopyrroles and pyridazines when combined with acyclic enamines. However, reactions with cyclic enamines gave the N-aminopyrroles, pyridazines, a dihydropyridazine as products as well as the noncyclized enamine intermediates. The noncyclized enamines could be converted to the N-aminopyrroles simply upon heating to higher temperatures, indicating a stepwise mechanism. The examples described here are the first reported cyclization reactions for dichloroazodienes.
- South, Michael S.,Jakuboski, Terri L.,Westmeyer, Mark D.,Daniel
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p. 8921 - 8934
(2007/10/03)
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- Methyl β-(benzotriazol-1-yl)vinyl ketone: A new β-acetylvinyl cation equivalent
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A simple and efficient two-step approach to methyl β-(benzotriazol-1-yl)vinyl ketone 7 is described. The synthetic utility of compound 7 has been demonstrated by nucleophilic substitutions of the benzotriazolyl group with a range of nucleophiles. Thus, me
- Katritzky, Alan R.,Blitzke, Torsten,Li, Jianqing
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p. 3773 - 3781
(2007/10/03)
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- REACTION OF 1-DIALKYLAMINO-1-BUTYN-3-ONES WITH HYDRAZINE AND SUBSTITUTED HYDRAZINES
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A series of 1-dialkylmino-1-butyn-3-ones were obtained, and their reactions with hydrazine and its alkyl, aryl and unsymmetrical dialkyl derivatives were studied.The reactions with unsubstituted and monosubstituted hydrazones lead to the formation of heterocyclic compounds of the pyrazole series, while the monosubstituted hydrazines form two isomeric products.Unsymmetrical dimethylhydrazine adds at the C1-carbon atom with the formation of compounds containing an open structure.
- Ostroumov, I. G.,Tsil'ko, A. E.,Maretina, I. A.,Petrov, A. A.
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p. 1467 - 1474
(2007/10/02)
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- REACTION OF 1-ETHOXY-1-BUTEN-3-ONE WITH AMINES
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In the reaction of 1-ethoxy-1-buten-3-one with ammonia and primary and secondary amines the alkoxy group is substituted by an amino group.In the reaction with ammonia 1-amino-1-buten-3-one condenses with the formation of 2-methyl-5-acetylpyridine.
- Markova, N. K.,Zaichenko, Yu. A.,Tsil'ko, A. E.,Maretina, I. A.
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p. 876 - 880
(2007/10/02)
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