Aqua-aminoorganoboron Catalyst: Engineering Single Water Molecule to Act as an Acid Catalyst in Nitro Aldol Reaction
作者:Junichi Yoshimoto、Christian A. Sandoval、Susumu Saito
DOI:10.1246/cl.2008.1294
日期:2008.12.5
We have disclosed the catalytic potential hidden behind a series of aqua-aminoorganoboron compounds in the formation and reaction of nitronate species. The pivotal role of a single-coordinated water molecule in the catalyst was demonstrated by comparison with the D2O-analogue. The present results provide a new strategy for the design of metal-free catalysts which function via elaborative hydrogen-bonding networks involving water.
Synthesis and Structure-Activity Correlation Studies of Secondary- and Tertiary-Amine-Based Glutathione Peroxidase Mimics
作者:Krishna P. Bhabak、Govindasamy Mugesh
DOI:10.1002/chem.200900818
日期:2009.9.28
In this study, a series of secondary‐ and tertiary‐amino‐substituted diaryl diselenides were synthesized and studied for their glutathioneperoxidase (GPx) like antioxidant activities with H2O2, cumene hydroperoxide, or tBuOOH as substrates and with PhSH or glutathione (GSH) as thiol cosubstrates. This study reveals that replacement of the tert‐amino groups in benzylamine‐based diselenides by sec‐amino
在这项研究中,合成了一系列仲和叔氨基取代的二芳基二硒化物,并研究了它们的谷胱甘肽过氧化物酶(GPx)的抗氧化活性,例如以H 2 O 2,枯烯氢过氧化物或t BuOOH为底物,以PhSH或谷胱甘肽为抗氧化剂。(GSH)作为硫醇共底物。这项研究表明,用仲氨基取代苄胺基二硒化物中的叔氨基可以显着增强芳族硫醇(PhSH)和GSH分析系统的催化活性。特别是,N-丙基和N-异丙基氨基取代的二硒化物的活性是相应的N,N的8-18倍当将GSH用作硫醇共底物时,在所有三个过氧化物系统中都使用基于二丙基胺和N,N-二异丙基胺的化合物。虽然催化机理仲丁基-氨基-取代的diselenides是类似于的叔基于胺的化合物,在一些关键中间体的稳定性和反应性的差异占在GPx的样活性的差异。观察到,在产生催化活性硒醇方面,仲氨基比叔氨基更好。这是由于在从基于仲胺的二硒化物衍生的硒烯基硫化物中不存在任何重要的硫醇交换反应。此外,硒酸(RSeO2
Reduction of base-stabilized difluoroboranes to induce rearrangement reactions
labelling experiments and diffusion control reactions, the formation of 5-H could be explained by a radical mechanism. The reduction of 4-pyr and 4-iPr using one-electron reducing agents also gave the rearranged products 13-pyr and 13-iPr in 21 and 19% yields, respectively, via C–N bond cleavage and B–N bond formation. The mechanism for the formation of 13-pyr and 13-iPr is suggested to contain a benzylic
Synthesis and characterization of diorganoantimony(III) and -bismuth(III) halides with 2-(Et2NCH2)C6H4 and 2-(i-Pr2NCH2)C6H4 substituents
作者:Ionuţ Chircă、Cristian Silvestru、Hans Joachim Breunig、Ciprian I. Raţ
DOI:10.1016/j.ica.2017.11.021
日期:2018.4
Abstract Compounds [2-(Et 2 NCH 2 )C 6 H 4 ] 2 SbX [X = Cl ( 1 ), Br ( 2 )] and [2-( i -Pr 2 NCH 2 )C 6 H 4 ] 2 EBr [E = Sb ( 3 ), Bi ( 4 )] were prepared by coupling reactions between organolithium derivatives or Grignard reagents and the corresponding metal halides. Compounds 1 – 4 were characterized in solution by multinuclear NMR spectroscopy, mass spectrometry and their molecular structures were