- Self-Condensation of Enaminodiones as a Method for Benzene Ring Construction: Synthesis of Diacyl-Substituted Phenols and Catechols
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A novel transition metal-free approach for the construction of the benzene core has been developed through self-condensation of available enaminodiones. Functionalized acyl-substituted phenols and catechols were obtained in 29-97% yields with high chemoselectivity under mild conditions. This base-promoted formal [4+2] annulation proceeds via cyclohexanone formation and involves the cascade transformation based on double Michael addition and aromatization (retro-Claisen cleavage and amine elimination).
- Obydennov, Dmitrii L.,Chernyshova, Elena V.,Sosnovskikh, Vyacheslav Y.
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p. 6491 - 6501
(2019/05/24)
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- 4-Hydroxyl-1,3 di-phthalate derivatives and preparation and application thereof
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The invention relates to 4-hydroxyl-1,3 di-phthalate derivative and preparation and application thereof. A compound is obtained by subjecting 4-hydroxyl-1,3 phthalic acid to esterification with various fatty alcohols or aromatic alcohols. The derivative h
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Paragraph 0035; 0036
(2017/01/02)
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- Aromatic nucleophilic substitution or CuI-catalyzed coupling route to martinellic acid
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Condensation of β-amino ester 8b with triflate 7 gives N-aryl amino ester 11, which is converted into 2-substituted 4-oxoquinoline 4 using an intramolecular Dieckmann reaction as the key step. CuI-mediated coupling of β-amino ester 8a with 1,4-diiodobenzene followed by an intramolecular acylation and Pd-catalyzed carbonylation provide another manner to 4. Alkylation of 4 and subsequent reductive amination deliver the cyclic imine 14, which is transformed into triamine 3 by ordinary operations. Guanylation of 3 under mild condition followed by deprotection results in the synthesis of martinellic acid 1.
- Ma, Dawei,Xia, Chengfeng,Jiang, Jiqing,Zhang, Jianhua,Tang, Wenjun
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p. 442 - 451
(2007/10/03)
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- Pyrimidine Derivatives and Related Compounds. 39. A Novel Cycloaromatization Reaction of 5-Formyl-1,3-dimethyluracil with Three-Carbon Nucleophiles. Synthesis of Substituted 4-Hydroxybenzoates
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Treatment of 5-formyl-1,3-dimethyluracil (1) with α-substituted acetone derivatives (C-C-C type nucleophiles) such as acetylacetone, acetoacetamide, ethyl acetoacetate, and phenylacetone in basic media affords the corresponding 4-hydroxybenzoates (4).On the other hand, treatment of 1 with cyanoacetamide, a C-C-N type nucleophile, gives the nicotinate 8.A mechanism for this cycloaromatization was proposed on the basis of reaction of 5-formyl-1,3-dimethyluracil-d1 (6) with acetylacetone.
- Hirota, Kosaku,Kitade, Yukio,Senda, Shigeo
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p. 3949 - 3953
(2007/10/02)
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