- Oxidation of Nonactivated Anilines to Generate N-Aryl Nitrenoids
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A low-temperature, protecting-group-free oxidation of 2-substituted anilines has been developed to generate an electrophilic N-aryl nitrenoid intermediate that can engage in C-NAr bond formation to construct functionalized N-heterocycles. The exposure of 2-substituted anilines to PIFA and trifluoroacetic acid or 10 mol percent Sc(OTf)3 triggers nitrenoid formation, followed by productive and selective C-NAr and C-C bond formation to yield spirocyclic- or bicyclic 3H-indoles or benzazepinones. Our experiments demonstrate the breadth of these oxidative processes, uncover underlying fundamental elements that control selectivity, and demonstrate how the distinct reactivity patterns embedded in N-aryl nitrenoid reactive intermediates can enable access to functionalized 3H-indoles or benzazepinones.
- Deng, Tianning,Mazumdar, Wrickban,Ford, Russell L.,Jana, Navendu,Izar, Ragda,Wink, Donald J.,Driver, Tom G.
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supporting information
p. 4456 - 4463
(2020/03/05)
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- I(III)-catalyzed oxidative cyclization - Migration tandem reactions of unactivated anilines
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An I(III)-catalyzed oxidative cyclization-migration tandem reaction using Selectfluor as the oxidant was developed that converts unactivated anilines into 3H-indoles is reported herein. The reaction requires as little as 1 mol % of the iodocatalyst and is mild, tolerating pyridine and thiophene functional groups, and the dependence of the diastereoselectivity of the process on the identity of the iodoarene or iodoalkane precatalyst suggests that the catalyst is present for the stereochemical determining C-N bond forming step.
- Deng, Tianning,Shi, Emily,Thomas, Elana,Driver, Tom G.
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supporting information
p. 9102 - 9106
(2020/11/13)
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- Achieving High Ortho Selectivity in Aniline C-H Borylations by Modifying Boron Substituents
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High ortho selectivity for Ir-catalyzed C-H borylations (CHBs) of anilines results when B2eg2 (eg = ethylene glycolate) is used as the borylating reagent in lieu of B2pin2, which is known to give isomeric mixtures with anilines lacking a blocking group at the 4-position. With this modification, high selectivities and good yields are now possible for various anilines, including those with groups at the 2- and 3-positions. Experiments indicate that ArylN(H)Beg species are generated prior to CHB and support the improved ortho selectivity relative to B2pin2 reactions arising from smaller Beg ligands on the Ir catalyst. The lowest-energy transition states (TSs) from density functional theory computational analyses have N-H···O hydrogen-bonding interactions between PhN(H)Beg and O atoms in Beg ligands. Ir-catalyzed CHB of PhN(H)Me with B2eg2 is also highly ortho-selective. 1H NMR experiments show that N-borylation fully generates PhN(Me)Beg prior to CHB. The TS with the lowest Gibbs energy was the ortho TS, in which the Beg unit is oriented anti to the bipyridine ligand.
- Smith, Milton R.,Bisht, Ranjana,Haldar, Chabush,Pandey, Gajanan,Dannatt, Jonathan E.,Ghaffari, Behnaz,Maleczka, Robert E.,Chattopadhyay, Buddhadeb
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p. 6216 - 6223
(2018/05/23)
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- Synthesis method of phosphorescent materials of homoleptic Ir complex including DMP ligands using microwave
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The present invention relates to a synthesis method capable of synthesizing an iridium compound based on dimethylphenyl (DMP) ligand with high yield and excellent process efficiency. More specifically, the present invention relates to a synthesis method which applies a microwave reactor and is capable of securing significantly improved yields over previously known yields using an iridium dimer structure during a reaction.COPYRIGHT KIPO 2018
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Paragraph 0134; 0135; 0156-0158
(2018/06/28)
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- FACTOR XIa INHIBITORS
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The present invention provides a compound of Formula (I) and pharmaceutical compositions comprising one or more said compounds, and methods for using said compounds for treating or preventing thromboses, embolisms, hypercoagulability or fibrotic changes. The compounds are selective Factor XIa inhibitors or dual inhibitors of Factor XIa and plasma Kallikrein.
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Page/Page column 45
(2017/05/21)
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- Control of the Chemoselectivity of Metal N-Aryl Nitrene Reactivity: C-H Bond Amination versus Electrocyclization
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A mechanism study to identify the elements that control the chemoselectivity of metal-catalyzed N-atom transfer reactions of styryl azides is presented. Our studies show that the proclivity of the metal N-aryl nitrene to participate in sp3-C-H bond amination or electrocyclization reactions can be controlled by either the substrate or the catalyst. Electrocyclization is favored for mono-β-substituted and sterically noncongested styryl azides, whereas sp3-C-H bond amination through an H-atom abstraction-radical recombination mechanism is preferred when a tertiary allylic reaction center is present. Even when a weakened allylic C-H bond is present, our data suggest that the indole is still formed through an electrocyclization instead of a common allyl radical intermediate. The site selectivity of metal N-aryl nitrenes was found to be controlled by the choice of catalyst: Ir(I)-alkene complexes trigger electrocyclization processes while Fe(III) porphyrin complexes catalyze sp3-C-H bond amination in substrates where Rh2(II) carboxylate catalysts provide both products.
- Kong, Chen,Jana, Navendu,Jones, Crystalann,Driver, Tom G.
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supporting information
p. 13271 - 13280
(2016/10/22)
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- Rh2(II)-catalyzed ester migration to afford 3 H-indoles from trisubstituted styryl azides
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Rh2(II)-Complexes trigger the formation of 3H-indoles from ortho-alkenyl substituted aryl azides. This reaction occurs through a 4π-electron-5-atom electrocyclization of the rhodium N-aryl nitrene followed by a [1,2]-migration to afford only 3H-indoles. The selectivity of the migration is dependent on the identity of the β-styryl substituent.
- Kong, Chen,Driver, Tom G.
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supporting information
p. 802 - 805
(2015/04/27)
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- Efficient synthesis of 3 H-indoles enabled by the lead-mediated α-arylation of β-ketoesters or γ-lactams using aryl azides
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The development of a lead-mediated α-arylation reaction between aryl azides and β-ketoesters or γ-lactams that facilitates the formation of 3H-indoles is disclosed. Twenty-five examples are included which demonstrate the generality of this reaction to access aryl azides bearing tetrasubstituted o-alkyl substituents. When paired with a Staudinger reduction, this reaction streamlines the synthesis of functionalized 3H-indoles.
- Zhou, Fei,Driver, Tom G.
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supporting information
p. 2916 - 2919
(2014/06/23)
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- Development of a Suzuki cross-coupling reaction between 2-azidoarylboronic pinacolate esters and vinyl triflates to enable the synthesis of [2,3]-fused indole heterocycles
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The scope and limitations of a Suzuki reaction between 2-azidoarylboronic acid pinacolate esters and vinyl triflates are reported. This cross-coupling reaction enables the regioselective synthesis of indoles after a subsequent RhII2-catalyzed sp2-C-H bond amination reaction.
- Jana, Navendu,Nguyen, Quyen,Driver, Tom G.
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p. 2781 - 2791
(2014/04/17)
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- A traceless directing group for C - H borylation
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Not a trace: Borylation of the nitrogen in nitrogen heterocycles or anilines provides a traceless directing group for subsequent catalytic C - H borylation. Selectivities that previously required Boc protection can be achieved; furthermore, the NBpin directing group can be installed and removed in situ, and product yields are substantially higher. Boc=tert-butoxycarbonyl, pin=pinacolato. Copyright
- Preshlock, Sean M.,Plattner, Donald L.,Maligres, Peter E.,Krska, Shane W.,Maleczka Jr., Robert E.,Smith III, Milton R.
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supporting information
p. 12915 - 12919
(2014/01/06)
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- Rh2(II)-catalyzed selective aminomethylene migration from styryl azides
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Rh2(II)-Carboxylate complexes were discovered to promote the selective migration of aminomethylenes in β,β-disubstituted styryl azides to form 2,3-disubstituted indoles. Mechanistic data are also presented that suggest that the migration occurs stepwise before diffusion of the iminium ion.
- Kong, Chen,Jana, Navendu,Driver, Tom G.
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supporting information
p. 824 - 827
(2013/03/29)
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- RhII2-catalyzed synthesis of α-, β-, or δ-carbolines from aryl azides
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Approaching all isomers: A range of α-, β- and δ-carbolinium ions are readily available from ortho-substituted aryl azides using a rhodium(II) carboxylate catalyst (see scheme). The carbolinium ions are readily reduced to afford tryptolines or deprotonated to access pyridoindoles. This [RhII2]-catalyzed C-H bond amination was used in the synthesis of (±)-horsfiline and neocryptolepine. esp=α,α,α',α'- tetramethyl-1,3-benzenedipropionate. Copyright
- Pumphrey, Ashley L.,Dong, Huijun,Driver, Tom G.
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supporting information; experimental part
p. 5920 - 5923
(2012/08/07)
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- FUSED HETEROTETRACYCLIC COMPOUNDS AND USE TEHREOF AS HCV POLYMERASE INHIBITOR
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The present invention relates to a tetracyclic fused heterocyclic compound represented by the following formula [I] wherein each symbol is as defined in the specification, or a pharmaceutically acceptable a salt thereof, and a hepatitis C virus (HCV) polymerase inhibitor and a therapeutic agent for hepatitis C containing this compound. The compound of the present invention shows an anti-HCV activity based on the HCV polymerase inhibitory activity, and useful as an agent for the prophylaxis or treatment of hepatitis C.
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Example 1-15
(2008/06/13)
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