- Base-promoted ring-closing carbonyl-allene metathesis for the synthesis of 2,4-disubstituted pyrroles
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A base-promoted ring-closing carbonyl-allene metathesis reaction of N-allenyl β-enaminones (generated in situ from N-propargyl β-enaminones) gives 2,4-disubstituted pyrroles with cleavage of the C(sp)-C(sp3) bond. This transition metal-free procedure generates 1 equiv. of acetic acid as the sole byproduct. A preliminary mechanistic study supports a stepwise [2 + 2] cycloaddition/retro [2 + 2] reaction pathway.
- Cheng, Guolin,Lv, Weiwei,Xue, Lulu
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p. 4414 - 4417
(2018/10/17)
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- Preparation method of 2,4-di-substituted pyrrole derivative
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The invention discloses a preparation method of a 2,4-di-substituted pyrrole derivative. The reaction equation is shown in the description. By adopting the method, a pyrrole derivative with a plurality of substituents which is difficult to obtain with other methods can be synthesized.
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Paragraph 0025; 0026; 0027; 0028; 0029; 0030; 0031
(2018/07/30)
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- Reaction between 4-Nitro-1,3-diarylbutan-1-ones and Ammonium Acetate in the Presence of Morpholine and Sulfur: An Efficient Synthesis of 2,4-Diarylpyrroles
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An efficient synthesis of 2,4-diarylpyrroles is described. Heating a mixture of a 4-nitro-1,3-diarylbutan-1-one and ammonium acetate in the presence of morpholine and sulfur afforded the corresponding 2,4-diarylpyrroles in excellent yields.
- Adib, Mehdi,Ayashi, Neda,Heidari, Fatemeh,Mirzaei, Peiman
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p. 1738 - 1742
(2016/07/06)
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- 2,4- vs 3,4-disubsituted pyrrole synthesis switched by copper and nickel catalysts
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A novel and efficient copper or nickel catalyzed highly selective denitrogenative annulation of vinyl azides with aryl acetaldehydes has been developed. 2,4- and 3,4-diaryl substituted pyrroles, which are difficult to synthesize by the reported methods, can be highly regioselectively prepared by this protocol simply switched by the selection of the transition metal catalysts. Compared with the reported acidic or basic conditions for polysubstituted pyrrole synthesis, the present reaction conditions are mild, neutral, and very simple without any additives.
- Chen, Feng,Shen, Tao,Cui, Yuxin,Jiao, Ning
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supporting information
p. 4926 - 4929,4
(2012/12/12)
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- A modular synthesis of unsymmetrical tetraarylazadipyrromethenes
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A stepwise route to unsymmetrical tetraarylazadipyrromethenes by a condensation of 2,4-diaryl-5-nitroso-pyrroles with 2,4-diarylpyrroles is described. This modular building-block approach allows for the introduction of up to four different aryl substituents on the azadipyrromethene and is tolerant of a varied substituent set. An efficient synthesis of the 2,4-diarylpyrroles building blocks from 1,3-diaryl-4-nitro-butan-1-ones by nitro hydrolysis to a keto-aldehyde and subsequent ammonia condensation reaction has been achieved. The facile conversion of 2,4-diarylpyrroles into their α-nitroso analogues by their reaction with sodium nitrite generated the second building block required for the synthesis.
- Hall, Michael J.,McDonnell, Shane O.,Killoran, John,O'Shea, Donal F.
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p. 5571 - 5578
(2007/10/03)
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