1003-29-8Relevant academic research and scientific papers
Visible-light mediated facile dithiane deprotection under metal free conditions
Dharpure, Pankaj D.,Bhowmick, Anindita,Warghude, Prakash K.,Bhat, Ramakrishna G.
, (2020)
Visible light mediated facile and selective dithiane deprotection under metal free conditions is developed. Eosin Y (1 mol%) proved to be an effective catalyst for the dithiane deprotection under the ambient photoredox conditions. The standard household compact fluorescent light source (CFL bulb) proved to be effective under open-air conditions in aqueous acetonitrile at room temperature. The protocol that exhibits a broad substrate scope and functional group tolerance has been shown to expand to a range of transformations for the electron-rich and -deficient thioacetals and thioketals. The synthetic utility of this protocol has also been demonstrated by gram-scale application.
Molybdenum complex with bulky chelates as a functional model for molybdenum oxidases
Leppin, Jana,F?rster, Christoph,Heinze, Katja
, p. 12416 - 12427 (2014)
The novel bulky Schiff base chelate ligand [(4,5-diisopropyl-1H-pyrrole-2-yl)methylene]-4-(tert-butyl)aniline (iPr2HL) bearing two isopropyl groups close to the pyrrole nitrogen atom reacts with MoCl2(dme)O2 (dme = 1,2-dimethoxyethane) to give the sterically congested complex MoVI(iPr2L)2O2 (iPr21; OC-6-4-4 configuration). In spite of the increased steric shielding of the [MoO2] unit iPr21 is active in oxygen-atom transfer to PMe3 and PPh3 to give OPMe3 and OPPh3, respectively. Because of the increased steric bulk of the chelate ligand, formation of dinuclear complexes [MoV(iPr2L)2O]2(μ-O) (iPr23) by comportionation is effectively prevented in contrast to the highly favored formation of [MoV(H2L)2O]2(μ-O) (H23) with the less bulky ligand H2HL. Instead, the smaller PMe3 ligand coordinates to the resulting pentacoordinate intermediate MoIV(iPr2L)2O (iPr25), giving the hexacoordinate complex MoIV(iPr2L)2O(PMe3) (iPr22) with OC-6-3-3 configuration. The larger potential ligands PPh3 and OPPh3 are only able to weakly coordinate to iPr25, giving labile and sensitive MoIV(iPr2L)2O(L) complexes (iPr26, L = PPh3; iPr27, L = OPPh3). Traces of water and dioxygen in solutions of iPr26/iPr27 yield the di(μ-oxido) complex [MoV(iPr2L)O]2(μ-O)2 (iPr24) with reduced steric congestion due to dissociation of the bulky chelate ligands. According to electron paramagnetic resonance studies, the much more strongly bound small PMe3 ligand in iPr22 can be slowly liberated by one-electron oxidation to MoV, with Ag+ leaving a free coordination site at MoV. Hence, essentially pentacoordinate MoIV and MoV complexes are accessible as a result of the increased steric bulk.
Schiff bases containing triphenylamine and pyrrole units: Synthesis and electrochromic, acidochromic properties
Li, Yu,Zhang, Yanhong,Niu, Haijun,Wang, Cheng,Qin, Chuanli,Bai, Xuduo,Wang, Wen
, p. 5245 - 5254 (2016)
Five Schiff bases (SBs) containing pyrrole and different triphenylamine (TPA) moieties were synthesized and the structures were confirmed by infrared spectroscopy (IR) and the nuclear magnetic resonance (NMR) technique. SB1 exhibited intense fluorescence emission in contrast to SB2-SB5. The electrochemical behaviors of the SBs were investigated by the cyclic voltammetry (CV) technique. SB2-SB5 exhibited redox stability with one well-defined and reversible redox couple upon electrochemical oxidation. On the contrary, SB1 revealed two oxidation peaks and one reduction peak in the first CV curve, followed by four well-defined redox couples in the steady-state CV curves. Electrochromic behaviors of the SBs have been observed, accompanied with a new absorption peak appearing with obvious color change from pale yellow neutral form to red oxidation form. SB1-SB5 also displayed sensitive acidochromic behaviors, and a linear dependence of maximum absorption wavelength as a function of pH values has been observed which proved the SBs could be used as alternative pH sensors in the given range.
Gold-catalyzed oxime-oxime rearrangement
Guven, Sinem,Ozer, Merve Sinem,Kaya, Serdal,Menges, Nurettin,Balci, Metin
, p. 2660 - 2663 (2015)
The gold-catalyzed reaction of pyrrole and indole oximes having a propargyl group attached to the nitrogen atom was studied. The selective 6-endo-dig mode of cyclization was observed for the terminal alkynes giving rise to the formation of pyrazine N-oxides in the presence of a gold catalyst. However, the reaction with substituted alkyne transferred the oxime functionality intramolecularly from one carbon atom to another via the 7-endo-dig cyclization process. This transformation is unprecedented in the literature and is named an oxime-oxime rearrangement.
Neutrophil-Selective Fluorescent Probe Development through Metabolism-Oriented Live-Cell Distinction
Gao, Min,Lee, Sun Hyeok,Park, Sang Hyuk,Ciaramicoli, Larissa Miasiro,Kwon, Haw-Young,Cho, Heewon,Jeong, Joseph,Chang, Young-Tae
, p. 23743 - 23749 (2021)
Human neutrophils are the most abundant leukocytes and have been considered as the first line of defence in the innate immune system. Selective imaging of live neutrophils will facilitate the in situ study of neutrophils in infection or inflammation events as well as clinical diagnosis. However, small-molecule-based probes for the discrimination of live neutrophils among different granulocytes in human blood have yet to be reported. Herein, we report the first fluorescent probe NeutropG for the specific distinction and imaging of active neutrophils. The selective staining mechanism of NeutropG is elucidated as metabolism-oriented live-cell distinction (MOLD) through lipid droplet biogenesis with the help of ACSL and DGAT. Finally, NeutropG is applied to accurately quantify neutrophil levels in fresh blood samples by showing a high correlation with the current clinical method.
Pincer ligands based on α-amino acids: I. Synthesis of polydentate ligands from pyrrole-2,5-dicarbaldehyde
Knizhnikov,Borisova,Yurashevich,Popova,Chernyad'ev,Zubreichuk,Reshetova
, p. 855 - 860 (2007)
New chiral pincer ligands having CH=N moieties were synthesized by condensation of 1H-pyrrole-2,5-dicarbaldehyde with l-methionine and l-histidine methyl esters. Their reduction under mild conditions (NaBH4, -30°C) gave the corresponding amine ligands in high yields. An improved procedure for the preparation of 1H-pyrrole-2,5-dicarbaldehyde was proposed.
Deprotection of N-sulfonyl nitrogen-heteroaromatics with tetrabutylammonium fluoride
Yasuhara, Akito,Sakamoto, Takao
, p. 595 - 596 (1998)
The deprotection of N-methylsulfonyl, N-(p-toluenesufonyl), and N-phenylsulfonyl nitrogen-heteroaromatic compounds proceeds easily in excellent yields by refluxing with tetrabutylammonium fluoride (TBAF) in THF.
Development of 5-(aminomethyl)pyrrole-2-carboxylic acid as a constrained surrogate of Gly-ΔAla and its application in peptidomimetic studies
Chakraborty, Tushar K,Krishna Mohan,Kiran Kumar,Kunwar, Ajit C
, p. 2589 - 2592 (2002)
A new peptidomimetic scaffold based on 5-(aminomethyl)pyrrole-2-carboxylic acid (1) is developed for the first time and used as a conformationally constrained surrogate of the Gly-ΔAla dipeptide isostere (2) to prepare peptides 3 and 4.
Effect of aromatic π-bridges on molecular structures and optoelectronic properties of A-π-D-π-A small molecular acceptors based on indacenodithiophene
Chen, Yueju,Liang, Jingtang,Shen, Ping,Wang, Linqiao,Weng, Chao,Yu, Yufu
, (2021)
Investigation on the relationship between molecular structure and device performance is of great important to develop highly efficient A-π-D-π-A small molecular acceptors (SMAs). However, there is still lack of a complete and in-depth study on effects of
Synthesis of some diethylphosphono substituted 3H-pyrrolizines
Loussouarn,Servant,Guervenou,Sturtz
, p. 275 - 285 (1996)
The preparation of various alkyl substituted monophosphonate 3H-pynolizines via a tandem Michael □ Horner-Emmons reaction is reported. These products were prepared from tetraethyl ethylidene gem-bisphosphonate and corresponding 2-acylpyrroles.
