- A Chiral Pentafluorinated Isopropyl Group via Iodine(I)/(III) Catalysis
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An I(I)/(III) catalysis strategy to construct an enantioenriched fluorinated isostere of the iPr group is reported. The difluorination of readily accessible α-CF3-styrenes is enabled by the in situ generation of a chiral ArIF2 species to forge a stereocentre with the substituents F, CH2F and CF3 (up to 95 %, >20:1 vicinal:geminal difluorination). The replacement of the metabolically labile benzylic proton results in a highly preorganised scaffold as was determined by X-ray crystallography (π→σ* and stereoelectronic gauche σ→σ* interactions). A process of catalyst editing is disclosed in which preliminary validation of enantioselectivity is placed on a structural foundation.
- Meyer, Stephanie,H?fliger, Joel,Sch?fer, Michael,Molloy, John J.,Daniliuc, Constantin G.,Gilmour, Ryan
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supporting information
p. 6430 - 6434
(2021/02/26)
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- Hypervalent Iodine(III)-Catalysed Enantioselective α-Acetoxylation of Ketones
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An enantioselective catalytic synthesis of α-acetoxylated ketones through I(I)/I(III) catalysis using a resorcinol/lactamide-based chiral iodoarene is reported. Catalyst turnover by in situ generation of the active iodine(III) derivative is achieved by oxidation with mCPBA in the presence of acetic acid. The prior transformation of ketones to easily accessible acetyl enol ethers is beneficial and yields up to 97 percent with enantioselectivities up to 88 percent ee are obtained using only low catalyst loadings of only 5 mol percent under mild reaction conditions.
- Hokamp, Tobias,Wirth, Thomas
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supporting information
p. 10417 - 10421
(2020/07/24)
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- Enantioselective Synthesis of 3-Fluorochromanes via Iodine(I)/Iodine(III) Catalysis
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The chromane nucleus is common to a plenum of bioactive small molecules where it is frequently oxidized at position 3. Motivated by the importance of this position in conferring efficacy, and the prominence of bioisosterism in drug discovery, an iodine(I)/iodine(III) catalysis strategy to access enantioenriched 3-fluorochromanes is disclosed (up to 7:93 e.r.). In situ generation of ArIF2 enables the direct fluorocyclization of allyl phenyl ethers to generate novel scaffolds that manifest the stereoelectronic gauche effect. Mechanistic interrogation using deuterated probes confirms a stereospecific process consistent with a type IIinv pathway.
- Daniliuc, Constantin G.,Gilmour, Ryan,Neufeld, Jessica,Sarie, Jér?me C.,Thiehoff, Christian
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supporting information
p. 15069 - 15075
(2020/06/17)
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- Enantioselective Construction of Tertiary Fluoride Stereocenters by Organocatalytic Fluorocyclization
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1,1-Disubstituted styrenes with internal oxygen and nitrogen nucleophiles undergo oxidative fluorocyclization reactions with in situ generated chiral iodine(III)-catalysts. The resulting fluorinated tetrahydrofurans and pyrrolidines contain a tertiary carbon-fluorine stereocenter. Application of a new 1-naphthyllactic acid-based iodine(III)-catalyst allows the control of tertiary carbon-fluorine stereocenters with up to 96% ee. Density functional theory calculations are performed to investigate the details of the mechanism and the factors governing the stereoselectivity of the reaction.
- Biosca, Maria,Eriksson, Lars,Hedberg, Martin,Himo, Fahmi,Lübcke, Marvin,Szabó, Kálmán J.,Wang, Qiang
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supporting information
p. 20048 - 20057
(2020/11/27)
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- Enantioselective Electrochemical Lactonization Using Chiral Iodoarenes as Mediators
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The enantioselective electrochemical lactonization of diketo acid derivatives using chiral iodoarenes as redox mediators is reported for the first time. Good to high stereoselectivities are observed in the lactonization and also in intermolecular α-alkoxylations of diketo ester derivatives. This enantioselective process was then adapted to an electrochemical flow microreactor where only small amounts of supporting electrolyte were necessary.
- Gao, Wen-Chao,Xiong, Zi-Yue,Pirhaghani, Shafigh,Wirth, Thomas
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supporting information
p. 276 - 284
(2019/01/04)
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- Enantioselective, Catalytic Vicinal Difluorination of Alkenes
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The enantioselective, catalytic vicinal difluorination of alkenes is reported by II/IIII catalysis using a novel, C2-symmetric resorcinol derivative. Catalyst turnover via in situ generation of an ArIIIIF2 species is enabled by Selectfluor oxidation and addition of an inexpensive HF–amine complex. The HF:amine ratio employed in this process provides a handle for regioselective orthogonality as a function of Br?nsted acidity. Selectivity reversal from the 1,1-difluorination pathway (geminal) to the desired 1,2-difluorination (vicinal) is disclosed (>20:1 in both directions). Validation with electron deficient styrenes facilitates generation of chiral bioisosteres of the venerable CF3 unit that is pervasive in drug discovery (20 examples, up to 94:06 e.r.). An achiral variant of the reaction is also presented using p-TolI (up to >95 % yield).
- Scheidt, Felix,Sch?fer, Michael,Sarie, Jér?me C.,Daniliuc, Constantin G.,Molloy, John J.,Gilmour, Ryan
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supporting information
p. 16431 - 16435
(2018/11/23)
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- Selective aryne formation via Grob fragmentation from the [2+2] cycloadducts of 3-triflyloxyarynes
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A chemoselective ring-opening protocol of the formal [2+2] cycloadducts of 3-triflyloxyarynes was developed to generate 2,3-aryne intermediate via Grob fragmentation. A variety of 1,3-di- and 1, 2, 3-trisubstituted arenes could be readily accessed through this [2+2] cycloaddition-2,3-aryne formation sequence. The regioselectivity in these transformations originates from the steric repulsion of the aliphatic chain.
- Shi, Jiarong,Xu, Hai,Qiu, Dachuan,He, Jia,Li, Yang
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supporting information
p. 623 - 626
(2017/05/15)
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- Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
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Molecular structures of the most prominent chiral non-racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen-bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts was extended to the enantioselective dioxygenation of alkenes. A series of terminal styrenes are converted into the corresponding vicinal diacetoxylation products under mild conditions and provide the proof of principle for a truly intermolecular asymmetric alkene oxidation under iodine(I/III) catalysis.
- Haubenreisser, Stefan,W?ste, Thorsten H.,Martnez, Claudio,Ishihara, Kazuaki,Muiz, Kilian
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supporting information
p. 413 - 417
(2016/01/25)
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- Stereoselective Ketone Rearrangements with Hypervalent Iodine Reagents
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The first stereoselective version of an iodine(III)-mediated rearrangement of arylketones in the presence of orthoesters is described. The reaction products, α-arylated esters, are very useful intermediates in the synthesis of bioactive compounds such as ibuprofen. With chiral lactic acid-based iodine(III) reagents product selectivities of up to 73 % ee have been achieved.
- Malmedy, Florence,Wirth, Thomas
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supporting information
p. 16072 - 16077
(2016/10/30)
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- 1 -HYDROXY-BENZOOXABOROLES AS ANTIPARASITIC AGENTS
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Provided are compounds useful for controlling endoparasites both in animals and agriculture. Further provided are methods for controlling endoparasite infestations of an animal by administering an effective amount of a compound as described above, or a pharmaceutically acceptable salt thereof, to an animal, as well as formulations for controlling endoparasite infestations using the compounds described above or an acceptable salt thereof, and an acceptable carrier. The claimed compounds are described by the following Markush formula:A typical example for a compound according to above formula is: A typical example for a compound according to above formula is:
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Page/Page column 54; 105-106
(2014/10/03)
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- Synthesis of polysubstituted benzofuran derivatives as novel inhibitors of parasitic growth
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A series of polysubstituted benzofuran derivatives was easily and rapidly prepared using a tandem Sonogashira coupling/cyclization reaction. Subsequent acylation afforded a small library of 39 new compounds that were assayed in cellulo on Plasmodium falci
- Thévenin, Marion,Thoret, Sylviane,Grellier, Philippe,Dubois, Jo?lle
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supporting information
p. 4885 - 4892
(2013/09/02)
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- Palladium-catalyzed intramolecular hydroarylation of 4-benzofuranyl alkynoates. Approach to angelicin derivatives
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Intramolecular hydroarylation of 4-benzofuranyl alkynoates using Pd(OAc)2 as catalyst took place selectively and efficiently, giving angular furocoumarin derivatives in high yields. The parent angelicin was obtained in 80% yield by this method.
- Kitamura, Tsugio,Otsubo, Kensuke
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experimental part
p. 2978 - 2982
(2012/05/04)
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- Rhodium-catalyzed regioselective carboacylation of olefins: A C-C bond activation approach for accessing fused-ring systems
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Cut and sew: A rhodium-catalyzed regioselective carboacylation reaction of benzocyclobutenones was developed (see scheme). Directed by the pendant olefins, the C1-C2 bond is selectively cleaved rather than the C1-C8 bond. Subsequent alkene insertion leads to complex fused-ring systems. This reaction provides facile access to natural-product-like polycyclic structures in a chemoselective and atom-economic fashion. Copyright
- Xu, Tao,Dong, Guangbin
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scheme or table
p. 7567 - 7571
(2012/09/22)
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- Ecofriendly iodination of activated aromatics and coumarins using potassium iodide and ammonium peroxodisulfate
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An environmentally benign protocol for the iodination of activated aromatics, such as phenols, anilines, and hydroxycou-marins, using inexpensive commercially available potassium iodide and ammonium peroxodisulfate (1:2.5 molar equivalents per mole of substrate) in aqueous methanol (MeOH-H 2O, 6:1) at room temperature has been developed. The protocol provides for ortho-selective monoiodination as the predominant product without added acid and it is compatible with a number of common oxidizible functional groups, such as formyl, benzylic C-H, aromatic amines and hydroxymethyl. Good to acceptable yields of monoiodinated products in acceptable reaction times and exclusive ortho-iodination for 7-hydroxycoumarins, despite the presence of vinylogous electronrich C3, are some of the key advantageous features of the method. Georg Thieme Verlag Stuttgart.
- Ganguly, Nemai C.,Barik, Sujoy Kumar,Dutta, Sanjoy
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experimental part
p. 1467 - 1472
(2010/09/16)
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- Diphenylprolinol-derived symmetrical and unsymmetrical chiral pincer palladium(II) and nickel(II) complexes: Synthesis via one-pot phosphorylation/metalation reaction and C-H activation
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The symmetrical P-stereogenic bis-phosphoramidite PCP pincer Pd(II) complexes 1 and 2 were easily prepared by a four-component, one-pot phosphorylation/palladation' procedure via C-H bond activation of the related ligands. In this synthetic procedure, (S)-diphenyl(pyrrolidin-2-yl)methanol was first phosphonated with PCl3 to afford the expected phosphorochloridate adduct, which then reacted in situ with resorcinol or disubstituted resorcinol, followed by treatment with PdCl2. The first examples of the unsymmetrical P-stereogenic phosphoramidite- and imidazoline-containing PCN pincer Pd(II) complex 3 and Ni(II) complex 4 could be obtained in a similar manner by using a chiral imidazoline-containing m-phenol derivative instead of resorcinol as a backbone. 31P NMR of the complexes confirmed the formation of a single diastereoisomer concerning the P-stereogenic center, and its absolute configuration was determined by an X-ray crystal structure determination. Preliminary investigations on the use of these complexes in the asymmetric allylation indicated that the unsymmetrical pincer Pd complex 3 exhibited higher catalytic activity than the related symmetrical ones. On the other hand, the more bulky Pd complex 2 gave better enantioselectivity, especially in the allylation of 4-nitrobenzenesulfonimine (69% ee).
- Niu, Jun-Long,Chen, Qing-Tao,Hao, Xin-Qi,Zhao, Qing-Xiang,Gong, Jun-Fang,Song, Mao-Ping
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scheme or table
p. 2148 - 2156
(2010/07/04)
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- Towards allosteric receptors - Synthesis of Resorcinarene-Functionalized 2,2′-Bipyridines and their metal complexes
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Based on a first: example of an allosteric hemicarcerand (1) we prepared four new 2,2′bipyridines that carry resorcinarene moieties in a highly convergent manner. Upon coordination to suitable transition metal ions or their complexes these compounds undergo conformational changes in a way that: they switch between "open" and. "closed" forms (2, 3, and 4) or vice versa (5), thus, bringing together or separating the two functional, moieties on the central, bipyridine, Among the transition metal complexes that act: as effectors for the conformational switching, [Re(CO)5Cl] and monomeric copper(I) complexes of sterically hindered 2,9-arylated 1,10-phenanthrolines proved, to be very effective.
- Staats, Holger,Eggers, Friederike,Hass, Oliver,Fahrenkrug, Frank,Matthey, Jens,Luening, Ulrich,Luetzen, Arne
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experimental part
p. 4777 - 4792
(2009/12/25)
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- The dynamic covalent chemistry of mono- and bifunctional boroxoaromatics
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10-Hydroxy-10,9-boroxophenanthrene reacts rapidly and reversibly with both benzylic and alkane diols in non-polar solvents. The formation of 2:1 adducts between the boroxoaromatic and the diols is favoured. The diol component of the adduct can be exchange
- Greig, Lyndsey M.,Slawin, Alexandra M.Z.,Smith, Melanja H.,Philp, Douglas
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p. 2391 - 2403
(2007/10/03)
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- POTENTIATORS OF GLUTAMATE RECEPTORS
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The present invention provides compounds of formula (I); pharmaceutical compositions thereof, and methods of using the same, processes or preparing the same, and intermediates thereof.
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Page/Page column 106
(2010/11/08)
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- The metal complex and homochiral diphosphines
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Novel chiral diphosphines (R) or (S), and their use as optically active ligand for preparing diphosphino-metallic complexes, and the diphosphino-metallic complexes containing said chiral diphosphines (R) or (S), and the use of the diphosphino-metallic com
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- Novel amines as histamine-3 receptor ligands and their therapeutic applications
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Compounds of formula (I) or a pharmaceutically acceptable salts or prodrug thereof which are useful for the modulation of the histamine-3 receptors in mammals and which are useful for the treatment of disorders ameliorated by histamine-3 receptor ligands.
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- Facile access to versatile polyaromatic building blocks: Selectively protected benzocyclobutenedione derivatives via regioselective [2 + 2] cycloaddition of α-alkoxybenzyne and ketene silyl acetal
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A facile, divergent access to highly oxygenated benzocyclobutene derivatives was developed via the regioselective [2 + 2] cycloaddition of α-alkoxybenzynes and ketene silyl acetals. The cycloadducts could be converted to selectively protected alkoxybenzocyclobutenediones, an attractive class of compounds for the synthesis of polyaromatic compounds. As one possible application, divergent access to a regioisomer pair of sulfonylphthalides for the Hauser approach to polyaromatic compounds is described.
- Hamura, Toshiyuki,Hosoya, Takamitsu,Yamaguchi, Hiroki,Kuriyama, Yokusu,Tanabe, Mitsujiro,Miyamoto, Makoto,Yasui, Yoshizumi,Matsumoto, Takashi,Suzuki, Keisuke
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p. 3589 - 3604
(2007/10/03)
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- A Facile Route to 3a,8a-Dihydrofurobenzofurans.
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Consecutive employment of palladium-catalysis and samarium(II)iodide-induced radical chemistry allows access to analogues of the ABC enol ether tricycle of aflatoxin B1 (1).The Pd-assisted coupling of tributylstannyl ethers of various 2-iodophenols with 2
- Holzapfel, Cedric W.,Williams, D. Bradley G.
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p. 8555 - 8564
(2007/10/02)
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