- Conformationally restricted 4-dimethylaminopyridine (DMAP) analogs: synthesis and evaluation of catalytic effectiveness
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The syntheses of a series of conformationally restricted 4-dimethylaminopyridine (DMAP) analogs 1-3 are described. Evaluations of catalyst effectiveness demonstrated that 1 was the best catalyst for the acetylation reaction of a tertiary alcohol, while 2
- Singh, Satwinder,Das, Goutam,Singh, Om V.,Han, Hyunsoo
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p. 1983 - 1986
(2007/10/03)
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- Modular design of pyridine-based acyl-transfer catalysts
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Derivatives of 3,4-diaminopyridine have been synthesized and studied as catalysts for acyl-transfer reactions. The design of these catalysts is guided by the stability of their acetyl intermediates as determined through theoretical calculations at the B3LYP/6-311 + G(d,p)//B3LYP/6-31G(d) level of theory. The most promising catalysts have been synthesized through a three- to five-step synthesis starting from 3,4-diaminopyridine. The catalytic activity has been determined for the acylation of 1-ethynylcyclohexanol with acetic anhydride at 23°C and with isobutyric anhydride at 40°C. For both reactions, the catalytic activity depends dramatically on the substitution pattern of the diaminopyridines. Best results are obtained with catalysts containing alkyl substituents at both amine nitrogens. Georg Thieme Verlag Stuttgart.
- Held, Ingmar,Xu, Shangjie,Zipse, Hendrik
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p. 1185 - 1196
(2008/02/02)
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- Facile synthesis of 9-azajulolidine and its application to post-Ullmann reactions
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This Letter describes the efficient synthesis of 9-azajulolidine from readily available reagents and its utilization as an effective electron-rich ligand for post-Ullmann-type reactions, that is, for C(aryl)-heteroatom (N, O, S) bond formation reactions, with dramatically enhanced reaction rates.
- Wong, Ken-Tsung,Ku, Sung-Yu,Yen, Feng-Wen
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p. 5051 - 5054
(2008/02/12)
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- Condensed Heteroaromatic Ring Systems. V. Formal Synthesis of Matrine and Related Compounds Using Palladium-Catalyzed Carbon-Carbon Bond Formations as Key Reactions
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The iodonation and subsequent dehydroxychlorination of 1,6-naphthyridin-5(6H)-one gave 5-chloro-8-iodo-1,6-naphthyridine, wich was converted to the 5-methoxy derivative.Starting from this compound, didehydromatrine was synthesized by using palladium-catalyzed cross-coupling reactions with ethyl acrylate and 3-butyn-1-ol, as key reactions.Similarly, nordehydro-α-matrinidine was synthesized through four steps from 8-bromo-1,6-naphthyridine, obtained by the bromination of unsubstituted 1,6-naphthyridine.Keywords - synthesis; matrine; didehydromatrine; nordehydro-α-matrinidine; palladium-catalyzed reaction; 1,6-naphthyridine; ethyl acrylate; 3-butyn-1-ol
- Sakamoto, Takao,Miura, Norio,Kondo, Yoshinori,Yamanaka, Hiroshi
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p. 2018 - 2023
(2007/10/02)
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