7148-68-7Relevant academic research and scientific papers
Column chromatography-free solution-phase synthesis of a natural piper-amide-like compound library
Kiim, Sumin,Lim, Chaemin,Lee, Sukjin,Lee, Seokwoo,Cho, Hyunkyung,Lee, Joo-Youn,Shim, Dong Sup,Park, Hee Dong,Kim, Sanghee
, p. 208 - 215 (2013/05/22)
We have achieved an efficient solution-phase parallel synthesis of a library of natural piper-amide-like compounds from the bifunctional β-phosphono-N-hydroxy-succinimidyl ester intermediate. The primary important feature in our study is the construction of natural-product-like molecules through the adaptation of sophisticated organic reactions that create water-soluble byproducts for a chromatography-free purification. This simple and efficient method rapidly provides a combinatorial library of high yield and purity. The library was evaluated against GPCR targets to demonstrate its potential use as a tool for drug discovery and in chemical biology.
Kinetics and Mechanism of Benzaldehyde Girard T Hydrazone Formation
Stachissini, Antonia Sonia,Amaral, Luciano do
, p. 1419 - 1424 (2007/10/02)
In aqueous solution, Girard T hydrazone formation from para-substituted benzaldehydes does not proceed to completion under the condition used.The corresponding equilibrium constants were determined and employed to calculate the rate of the reaction at completion.For all the reactions studied, the pH-rate profiles, extrapolated to zero buffer concentration, show one break at pH 4-5, characteristic of a change in the rate-determining step from carbinolamine dehydration to carbinolamine formation upon going from pH 7 to pH 1.The formation of the carbinolamine is subject to catalysis by hydronium ion and by carboxylic acids present in the buffers used to maintain pH.Broensted α values for this catalysis varied from 0.19 to 0.37.Rate constants for the cyanoacetic, chloroacetic, and formic acid catalyzed formation of carbinolamine from the para-substituted benzaldehydes correlate with ?+ substituent constants, giving a value of ρ+ equal to 0.70.Rate constants for the hydronium ion catalyzed formation of the carbinolamine from the same benzaldehydes are, however, insensitive to the substituent effect.These observations lead to the conclusion that the reactions occur by different routes as a function of the catalyst.We suggest a stepwise preassociation mechanism for the reaction catalyzed by carboxylic acids and a concerted preassociation mechanism for that catalyzed by hydronium ion.
