1325231-85-3Relevant academic research and scientific papers
Switching between Anion-Binding Catalysis and Aminocatalysis with a Rotaxane Dual-Function Catalyst
Eichstaedt, Katarzyna,Jaramillo-Garcia, Javier,Leigh, David A.,Marcos, Vanesa,Pisano, Simone,Singleton, Thomas A.
, p. 9376 - 9381 (2017)
The "off" state for aminocatalysis by a switchable [2]rotaxane is shown to correspond to an "on" state for anion-binding catalysis. Conversely, the aminocatalysis "on" state of the dual-function rotaxane is inactive in anion-binding catalysis. Switching b
Digging the Sigma-Hole of Organoantimony Lewis Acids by Oxidation
Yang, Mengxi,Tofan, Daniel,Chen, Chang-Hong,Jack, Kevin M.,Gabba?, Fran?ois P.
, p. 13868 - 13872 (2018)
The development of group 15 Lewis acids is an area of active investigation that has led to numerous advances in anion sensing and catalysis. While phosphorus has drawn considerable attention, emerging research shows that organoantimony(III) reagents may a
Iodine(III) Derivatives as Halogen Bonding Organocatalysts
Heinen, Flemming,Engelage, Elric,Dreger, Alexander,Weiss, Robert,Huber, Stefan M.
, p. 3830 - 3833 (2018)
Hypervalent iodine(III) derivatives are known as versatile reagents in organic synthesis, but there is only one previous report on their use as Lewis acidic organocatalysts. Herein, we present first strong indications for the crucial role of halogen bonding in this kind of catalyses. To this end, the solvolysis of benzhydryl chloride and the Diels–Alder reaction of cyclopentadiene with methyl vinyl ketone served as benchmark reactions for halide abstraction and the activation of neutral compounds. Iodolium compounds (cyclic diaryl iodonium species) were used as activators or catalysts, and we were able to markedly reduce or completely switch off their activity by sterically blocking one or two of their electrophilic axes. Compared with previously established bidentate cationic halogen bond donors, the monodentate organoiodine derivatives used herein are at least similarly active (in the Diels–Alder reaction) or even decidedly more active (in benzhydryl chloride solvolysis).
Carbon–Halogen Bond Activation by Selenium-Based Chalcogen Bonding
Wonner, Patrick,Vogel, Lukas,Düser, Maximilian,Gomes, Luís,Kniep, Florian,Mallick, Bert,Werz, Daniel B.,Huber, Stefan M.
, p. 12009 - 12012 (2017)
Chalcogen bonding is a little explored noncovalent interaction similar to halogen bonding. This manuscript describes the first application of selenium-based chalcogen bond donors as Lewis acids in organic synthesis. To this end, the solvolysis of benzhydr
Towards redox-switchable organocatalysts based on bidentate halogen bond donors
Engelage,Hijazi,Gartmann,Chamoreau,Sch?llhorn,Huber,Fave
, p. 4344 - 4352 (2021)
Redox-active bidentate halogen bond donors based on halopyridinium groups as halogen-bond donating units were synthesized and their structures were elucidated by X-ray diffraction analyses and DFT calculations.Viareversible twofold reduction, these dicationic species can be transformed to neutral compounds which should be much weaker Lewis acids. The corresponding electrochemical data were obtained, and CV as well as UV-vis and NMR techniques were also used to determine binding constants of these halogen bond donors to halides. While all titrations agree on the relative order of binding strengths (with chloride being bound strongest), there are marked deviations in the overall affinity constants which are discussed. In contrast to earlier azo-bridge analogues, the ethylene-linked variants presented herein do not oxidize halides, and thus the novel halogen bond donors could also be used as Lewis acidic organocatalysts in a halide abstraction benchmark reaction, yielding a performance similar to bis(haloimidazolium)-derived catalysts.
Chalcogen-Bonding Catalysis: From Neutral to Cationic Benzodiselenazole Scaffolds
Benz, Sebastian,Besnard, Celine,Matile, Stefan
, (2018)
Benzodiselenazoles (BDS) are emerging as privileged structures for chalcogen-bonding catalysis in the focal point of conformationally immobilized σ holes on strong selenium donors in a neutral scaffold. Whereas much attention has been devoted to work out
Corrigendum to: Digging the Sigma-Hole of Organoantimony Lewis Acids by Oxidation (Angewandte Chemie International Edition, (2018), 57, 42, (13868-13872), 10.1002/anie.201808551)
Yang, Mengxi,Tofan, Daniel,Chen, Chang-Hong,Jack, Kevin M.,Gabba?, Fran?ois P.
, p. 16929 - 16929 (2018)
In Scheme of this Communication, the representation of the hydrogen atoms in the hydrogenation products lacked consistency. The color code used for the hydrogen atoms was also erroneous. A corrected version of Scheme is shown below. None of the conclusion
Dicationic oligotelluroxane or mononuclear telluronium cation? Elucidation of the true catalytic species and activation mechanism of the benzylic carbon-halogen bond
Kikkawa, Shoko,Sakakibara, Nao,Takagi, Koji,Tsuzuki, Seiji
supporting information, p. 13736 - 13739 (2021/12/27)
The application of diaryltelluronium cations as chalcogen bonding organocatalysts was investigated for the Ritter-like reaction using time-course NMR analysis. The resistance to water of dicationic oligotelluroxanes differed depending on the oligomer chai
N-Heterocyclic Iod(az)olium Salts – Potent Halogen-Bond Donors in Organocatalysis
Boelke, Andreas,Kuczmera, Thomas J.,Lork, Enno,Nachtsheim, Boris J.
supporting information, p. 13128 - 13134 (2021/08/09)
This article describes the application of N-heterocyclic iod(az)olium salts (NHISs) as highly reactive organocatalysts. A variety of mono- and dicationic NHISs are described and utilized as potent XB-donors in halogen-bond catalysis. They were benchmarked in seven diverse test reactions in which the activation of carbon- and metal-chloride bonds as well as carbonyl and nitro groups was achieved. N-methylated dicationic NHISs rendered the highest reactivity in all investigated catalytic applications with reactivities even higher than all previously described monodentate XB-donors based on iodine(I) and (III) and the strong Lewis acid BF3.
Preorganization: A Powerful Tool in Intermolecular Halogen Bonding in Solution
Voelkel, Martin H. H.,Wonner, Patrick,Huber, Stefan Matthias
, p. 214 - 224 (2020/03/10)
Preorganization is a powerful tool in supramolecular chemistry which has been utilized successfully in intra- and intermolecular halogen bonding. In previous work, we had developed a bidentate bis(iodobenzimidazolium)-based halogen bond donor which featured a central trifluoromethyl substituent. This compound showed a markedly increased catalytic activity compared to unsubstituted bis(iodoimidazolium)-based Lewis acids, which could be explained either by electronic effects (the electron withdrawal by the fluorinated substituent) or by preorganization (the hindered rotation of the halogen bonding moieties). Herein, we systematically investigate the origin of this increased Lewis acidity via a comparison of the two types of compounds and their respective derivatives with or without the central trifluoromethyl group. Calorimetric measurements of halide complexations indicated that preorganization is the main reason for the higher halogen bonding strength. The performance of the catalysts in a series of benchmark reactions corroborates this finding.
