185303-22-4Relevant articles and documents
Iodine-Catalyzed Diels-Alder Reactions
Arndt, Thiemo,Wagner, Philip K.,Koenig, Jonas J.,Breugst, Martin
, p. 2922 - 2930 (2021/05/17)
The Diels-Alder cycloaddition is the most popular pericyclic reaction with numerous applications in synthesis and catalysis. We now demonstrate that we can perform this reaction under mild and metal-free conditions relying on molecular iodine as the catalyst. Cycloadditions with cyclohexadiene, cyclopentadiene, or isoprene with various dienophiles can be performed typically within minutes in moderate to good yields and high endo selectivity. The mechanistic studies including kinetic and DFT investigations clearly indicate a halogen-bond activation and rule out other modes of activation. Furthermore, iodine performs equally well as typical metallic Lewis acids like AlCl3, SnCl4, or TiCl4.
A Bidentate Iodine(III)-Based Halogen-Bond Donor as a Powerful Organocatalyst**
Heinen, Flemming,Reinhard, Dominik L.,Engelage, Elric,Huber, Stefan M.
supporting information, p. 5069 - 5073 (2021/02/26)
In contrast to iodine(I)-based halogen bond donors, iodine(III)-derived ones have only been used as Lewis acidic organocatalysts in a handful of examples, and in all cases they acted in a monodentate fashion. Herein, we report the first application of a bidentate bis(iodolium) salt as organocatalyst in a Michael and a nitro-Michael addition reaction as well as in a Diels–Alder reaction that had not been activated by noncovalent organocatalysts before. In all cases, the performance of this bidentate XB donor distinctly surpassed the one of arguably the currently strongest iodine(I)-based organocatalyst. Bidentate coordination to the substrate was corroborated by a structural analysis and by DFT calculations of the transition states. Overall, the catalytic activity of the bis(iodolium) system approaches that of strong Lewis acids like BF3.
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.
Bis-selenonium Cations as Bidentate Chalcogen Bond Donors in Catalysis
He, Xinxin,Wang, Xinyan,Tse, Ying-Lung Steve,Ke, Zhihai,Yeung, Ying-Yeung
, p. 12632 - 12642 (2021/10/21)
Lewis acids are frequently employed in catalysis but they often suffer from high moisture sensitivity. In many reactions, catalysts are deactivated because of the problem that strong Lewis acids also bond to the products. In this research, hydrolytically stable bidentate Lewis acid catalysts derived from selenonium dicationic centers have been developed. The bis-selenonium catalysts are employed in the activation of imine and carbonyl groups in various transformations with good yields and selectivity. Lewis acidity of the bis-selenonium salts was found to be stronger than that of the monoselenonium systems, attributed to the synergistic effect of the two cationic selenonium centers. In addition, the bis-selenonium catalysts are not inhibited by strong bases or moisture.
STRONGLY LEWIS ACIDIC METAL-ORGANIC FRAMEWORKS FOR CONTINUOUS FLOW CATALYSIS
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Paragraph 0186-0187, (2021/02/26)
Lewis acidic metal-organic framework (MOF) materials comprising triflate-coordinated metal nodes are described. The materials can be used as heterogenous catalysts in a wide range of organic group transformations, including Diels-Alder reactions, epoxide-ring opening reactions, Friedel-Crafts acylation reactions and alkene hydroalkoxylation reactions. The MOFs can also be prepared with metallated organic bridging ligands to provide heterogenous catalysts for tandem reactions and/or prepared as composites with support particles for use in columns of continuous flow reactor systems. Methods of preparing and using the MOF materials and their composites are also described.
Strongly Lewis Acidic Metal-Organic Frameworks for Continuous Flow Catalysis
Ji, Pengfei,Feng, Xuanyu,Oliveres, Pau,Li, Zhe,Murakami, Akiko,Wang, Cheng,Lin, Wenbin
supporting information, p. 14878 - 14888 (2019/10/02)
The synthesis of highly acidic metal-organic frameworks (MOFs) has attracted significant research interest in recent years. We report here the design of a strongly Lewis acidic MOF, ZrOTf-BTC, through two-step transformation of MOF-808 (Zr-BTC) secondary building units (SBUs). Zr-BTC was first treated with 1 M hydrochloric acid solution to afford ZrOH-BTC by replacing each bridging formate group with a pair of hydroxide and water groups. The resultant ZrOH-BTC was further treated with trimethylsilyl triflate (Me3SiOTf) to afford ZrOTf-BTC by taking advantage of the oxophilicity of the Me3Si group. Electron paramagnetic resonance spectra of Zr-bound superoxide and fluorescence spectra of Zr-bound N-methylacridone provided a quantitative measurement of Lewis acidity of ZrOTf-BTC with an energy splitting (?E) of 0.99 eV between the ?x? and ?y? orbitals, which is competitive to the homogeneous benchmark Sc(OTf)3. ZrOTf-BTC was shown to be a highly active solid Lewis acid catalyst for a broad range of important organic transformations under mild conditions, including Diels-Alder reaction, epoxide ring-opening reaction, Friedel-Crafts acylation, and alkene hydroalkoxylation reaction. The MOF catalyst outperformed Sc(OTf)3 in terms of both catalytic activity and catalyst lifetime. Moreover, we developed a ZrOTf-BTC?SiO2 composite as an efficient solid Lewis acid catalyst for continuous flow catalysis. The Zr centers in ZrOTf-BTC?SiO2 feature identical coordination environment to ZrOTf-BTC based on spectroscopic evidence. ZrOTf-BTC?SiO2 displayed exceptionally high turnover numbers (TONs) of 1700 for Diels-Alder reaction, 2700 for epoxide ring-opening reaction, and 326 for Friedel-Crafts acylation under flow conditions. We have thus created strongly Lewis acidic sites in MOFs via triflation and constructed the MOF?SiO2 composite for continuous flow catalysis of important organic transformations.
Borenium ionic liquids as catalysts for Diels-Alder reaction: Tuneable Lewis superacids for catalytic applications
Matuszek,Coffie,Chrobok,Swad?ba-Kwa?ny
, p. 1045 - 1049 (2017/08/15)
Ionic liquids based on the tricoordinate borenium cation were used for the first time as Lewis acid catalysts for a model Diels-Alder reaction. The conversion of the dienophile was successfully correlated with the Gutmann acceptor number values of the ionic liquids. Borenium ionic liquids exceeded the performance of catalysts reported in the literature.
BTK INHIBITORS
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Page/Page column 143; 144, (2016/07/27)
Provided are Bruton's Tyrosine Kinase (Btk) inhibitor compounds according to Formula I, or pharmaceutically acceptable salts thereof, or pharmaceutical compositions comprising these compounds and their use in therapy. In particular, provided is the use of Btk inhibitor compounds of Formula I in the treatment of Btk mediated disorders.
COMPOUNDS USEFUL AS MODULATORS OF TRPM8
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Paragraph 0578, (2016/03/29)
The present invention includes compounds useful as modulators of TRPM8, such as compounds of Formulae (Ia), (Ib) and (Ic), and the subgenus and species thereof; personal products containing those compounds; and the use of those compounds and the personal products, particularly the use of increasing or inducing chemesthetic sensations, such as cooling or cold sensations.
A Well-Defined Aluminum-Based Lewis Acid as an Effective Catalyst for Diels-Alder Transformations
Liu, Zhizhou,Lee, Jazreen Hui Qi,Ganguly, Rakesh,Vidovic, Dragoslav
supporting information, p. 11344 - 11348 (2015/08/03)
A catalytically active aluminum-based system for Diels-Alder transformations is reported. The system was generated by mixing a β-diketiminate-stabilized aluminum bistriflate compound with Na[BArCl4] (ArCl=3,5-Cl2C6H3). Solid-state analysis of the catalytic system reveals a unique structure incorporating a two-dimensional coordination polymer. According to the experimental results obtained from several Diels-Alder transformations, the aluminum-based system appears to be a more practical and more robust alternative to the recently reported compounds based on carbon and silicon cations.
