72709-61-6Relevant articles and documents
Supramolecular autoregulation
Rodríguez-Llansola, Francisco,Meijer
, p. 6549 - 6553 (2013)
Enzyme activity in biological systems is often governed by control mechanisms in which the catalytic properties are made sensitive or insensitive to differences in enzyme or substrate concentration. Here, we report the first supramolecular system where th
Asymmetric Catalysis, CIII [1]: Enantioselective Michael Addition of 1,3-Dicarbonyl Compounds to Conjugated Nitroalkenes
Brunner,Kimel
, p. 1063 - 1072 (1996)
Optically active Michael adducts were synthesized by addition of 1,3-dicarbonyl compounds to conjugated nitroalkenes. Good chemical yields were obtained for nitroalkenes stabilized by an aromatic substituent without any further substituents at the double
Computational Investigations of Enantioselection in Carbon-Carbon Bond Forming Reactions of Ruthenium Guanidinobenzimidazole Second Coordination Sphere Hydrogen Bond Donor Catalysts
Wititsuwannakul, Taveechai,Mukherjee, Tathagata,Hall, Michael B.,Gladysz, John A.
, p. 1149 - 1162 (2020)
The NH2 group of 2-guanidinobenzimidazole (GBI) can be replaced by (RCRC)-NHCH(CH2)4CHNMe2 and elaborated to the enantiopure chelate salts (SRuRCRC)-[(η5-C5H5)Ru(CO)(GBICH(CH2)4CHNMe2)]+PF6- ((SRuRCRC)-2+PF6-) and (RRuRCRC)-2+PF6-. These catalyze highly e
1,4-Michael additions of cyclic-β-ketoesters catalyzed by DNA in aqueous media
Izquierdo, Cristina,Luis-Barrera, Javier,Fraile, Alberto,Alemán, José
, p. 10 - 14 (2014)
In this work, we describe the 1,4-Michael addition of the 1,3-dicarbonyl compounds to activated ethylenes under st-DNA catalysis in water. The reaction of the β-ketoester 4 with nitroolefins and conjugated carbonyls proceeds quite well, whereas other less
Synthesis, characterization and catalytic performance in enantioselective reactions by mesoporous silica materials functionalized with chiral thiourea-amine ligand
G?k, Ya?ar,G?k, Halil Zeki
, p. 853 - 874 (2020/11/10)
Chiral heterogeneous catalysts have been synthesized by grafting of silyl derivatives of (1R, 2R)- or (1S, 2S)-1,2-diphenylethane-1,2-diamine on SBA-15 mesoporous support. The mesoporous material SBA-15 and so-prepared chiral heterogeneous catalysts were characterized by a combination of different techniques such as X-ray diffractometry (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) surface area. Results showed that (1R, 2R)- and (1S, 2S)-1,2-diphenylethane-1,2-diamine were successively immobilized on SBA-15 mesoporous support. Chiral heterogeneous catalysts and their homogenous counterparts were tested in enantioselective transfer hydrogenation of aromatic ketones and enantioselective Michael addition of acetylacetone to β-nitroolefin derivatives. The catalysts demonstrated notably high catalytic conversions (up to 99%) with moderate enantiomeric excess (up to 30% ee) for the heterogeneous enantioselective transfer hydrogenation. The catalytic performances for enantioselective Michael reaction showed excellent activities (up to 99%) with poor enantioselectivities. Particularly, the chiral heterogeneous catalysts could be readily recycled for Michael reaction and reused in three consecutive catalytic experiments with no loss of catalytic efficacies.
Novel 1,2,3-triazole epicinchonas: Transitioning from organocatalysis to biological activities
Barrulas, Pedro,Carreiro, Elisabete P.,Veiros, Luis F.,Amorim, Ana C.,Gut, Giri,Rosenthal, Philip J.,López, óscar,Puerta, Adrián,Padrón, José M.,Fernández-Bola?os, José G.,Burke, Anthony J.
, p. 2954 - 2974 (2021/08/24)
A small family of novel modular monofunctional epicinchonidine-1,2,3-triazole compounds was prepared in very good overall yield (3 steps from cinchonidine, 49–87% yield) using simple Cu(I) catalyzed click-chemistry. The objective of this study was to acce
Molecular Engineering of β-Substituted Oxoporphyrinogens for Hydrogen-Bond Donor Catalysis
Chahal, Mandeep K.,Payne, Daniel T.,Matsushita, Yoshitaka,Labuta, Jan,Ariga, Katsuhiko,Hill, Jonathan P.
, p. 82 - 90 (2020/01/02)
A new class of bifunctional hydrogen-bond donor organocatalyst using oxoporphyrinogens having increased intramolecular hydrogen-bond donor distances is reported. Oxoporphyrinogens are highly non-planar rigid macrocycles containing a multiple hydrogen bond-forming binding site. In this work, we describe the first example of non-planar OxPs as hydrogen-bond donor catalysts prepared using a molecular engineering approach of the binding site for dual activation of substrates. The introduction of β-substituents is key to the catalytic activity and the catalysts are able to catalyze 1,4-conjugate additions and sulfa-Michael additions, as well as, Henry and aza-Henry reactions at low catalyst loadings (≤ 1 mol-%) under mild conditions. Preliminary mechanistic studies have been carried out and a possible reaction mechanism has been proposed based on the bi-functional activation of both substrates through hydrogen-bonding interactions.
Novel carbohydrate-based thioureas as organocatalysts for asymmetric michael addition of 1,3-dicarbonyl compounds to nitroolefins
Ron?ák, Róbert,Tvrdoňová, Monika,Gonda, Jozef,Ele?ko, Ján
, (2020/06/24)
A series of novel carbohydrate-derived thioureas were synthesized and examined as catalysts for the asymmetric Michael addition of symmetrical 1,3-dicarbonyl compounds, including dimethyl malonate, to several trans-β-nitrostyrenes. High enantioselectiviti
Readily accessible mesoporous silica nanoparticles supported chiral urea-amine bifunctional catalysts for enantioselective reactions
G?k, Ya?ar,Aykut, ?rem Tutkum,G?k, Halil Zeki
, (2020/10/12)
The main objective of this study is to develop readily accessible and recyclable solid catalysts for enantioselective reactions. To achieve this, magnetic MCM-41 and non-magnetic SBA-15 mesoporous supports were prepared, then mesoporous silica supported c
Squaramide-decorated covalent organic framework as a new platform for biomimetic hydrogen-bonding organocatalysis
Li, Xia,Wang, Zhifang,Sun, Jiaxing,Gao, Jia,Zhao, Yu,Cheng, Peng,Aguila, Briana,Ma, Shengqian,Chen, Yao,Zhang, Zhenjie
supporting information, p. 5423 - 5426 (2019/05/16)
A squaramide-decorated COF was synthesized and used as a highly efficient heterogeneous catalyst for hydrogen-bonding organocatalysis as exemplified in the context of catalyzing Michael addition reactions under mild conditions. Our work lays a foundation
