- Iridium-catalyzed C-H borylation of heteroarenes: Scope, regioselectivity, application to late-stage functionalization, and mechanism
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A study on the iridium-catalyzed C-H borylation of heteroarenes is reported. Several heteroarenes containing multiple heteroatoms were found to be amenable to C-H borylation catalyzed by the combination of an iridium(I) precursor and tetramethylphenanthroline. The investigations of the scope of the reaction led to the development of powerful rules for predicting the regioselectivity of borylation, foremost of which is that borylation occurs distal to nitrogen atoms. One-pot functionalizations are reported of the heteroaryl boronate esters formed in situ, demonstrating the usefulness of the reported methodology for the synthesis of complex heteroaryl structures. Application of this methodology to the synthesis and late-stage functionalization of biologically active compounds is also demonstrated. Mechanistic studies show that basic heteroarenes can bind to the catalyst and alter the resting state from the olefin-bound complex observed during arene borylation to a species containing a bound heteroarene, leading to catalyst deactivation. Studies on the origins of the observed regioselectivity show that borylation occurs distal to N-H bonds due to rapid N-H borylation, creating an unfavorable steric environment for borylation adjacent to these bonds. Computational studies and mechanistic studies show that the lack of observable borylation of C-H bonds adjacent to basic nitrogen is not the result of coordination to a bulky Lewis acid prior to C-H activation, but the combination of a higher-energy pathway for the borylation of these bonds relative to other C-H bonds and the instability of the products formed from borylation adjacent to basic nitrogen.
- Larsen, Matthew A.,Hartwig, John F.
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supporting information
p. 4287 - 4299
(2014/04/03)
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- Compositions and Methods for Inhibition of TBL-1 Binding to Disease-Associated Molecules
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Compositions and methods which modulate diseases and disorders related to transducin β-like protein 1 (TBL1) activity, including but not limited to cancer, inflammation, and bone related diseases.
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Paragraph 0127
(2013/05/22)
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- HETEROARYL COMPOUNDS, COMPOSITIONS THEREOF, AND METHODS OF TREATMENT THEREWITH
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Provided herein are Heteroaryl Compounds having the following structure: (I) wherein R1, R2, L, X, Y, Z, Q, A and B are as defined herein, compositions comprising an effective amount of a Heteroaryl Compound and methods for treating or preventing cancer, inflammatory conditions, immunological conditions, metabolic conditions and conditions treatable or preventable by inhibition of a kinase pathway comprising administering an effective amount of a Heteroaryl Compound to a patient in need thereof.
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Page/Page column 181
(2008/12/05)
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- TRIAZOLOPYRAZINE COMPOUNDS USEFUL FOR THE TREATMENT OF DEGENERATIVE & INFLAMMATORY DISEASES
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Novel [1.2.4]triazolo[1,5-a]pyrazine compounds are disclosed that have a formula represented by the following (formula I). The compounds may be prepared as pharmaceutical compositions, and may be used for the prevention and treatment of a variety of conditions in mammals including humans, including by way of non-limiting example, arthritis, inflammation, and others.
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Page/Page column 50-51
(2008/06/13)
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