5676-57-3Relevant articles and documents
METHODS AND COMPOSITIONS FOR MODULATING SPLICING
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, (2020/08/22)
Described herein are small molecule splicing modulator compounds that modulate splicing of mRNA, such as pre-mRNA, encoded by genes, and methods of use of the small molecule splicing modulator compounds for modulating splicing and treating diseases and conditions.
Pd-Catalyzed Cross-Coupling Reactions Promoted by Biaryl Phosphorinane Ligands
Laffoon, Joshua D.,Chan, Vincent S.,Fickes, Michael G.,Kotecki, Brian,Ickes, Andrew R.,Henle, Jeremy,Napolitano, José G.,Franczyk, Thaddeus S.,Dunn, Travis B.,Barnes, David M.,Haight, Anthony R.,Henry, Rodger F.,Shekhar, Shashank
, p. 11691 - 11708 (2019/12/02)
We report the use of biaryl phosphorinanes as ligands for Pd-catalyzed cross-coupling reactions. A modular synthesis was developed that employs a double conjugate addition of primary biaryl phosphines into 1,1,5,5-tetraalkyl penta-1,4-diene-3-ones. Notably, this synthesis does not require the use of copper, a known contaminant in structurally related biaryl phosphane ligands. Using the synthetic strategy described above, we synthesized a library of biaryl phosphorinanes, varying their substitution about phosphorus and the steric and electronic nature of the biaryl motif. We then benchmarked their performance as ligands in Pd-catalyzed cross coupling reactions such as aryl sulfonamidation, aryl alkoxylation, and aryl amination in the presence of soluble organic bases. In each reaction studied, many ligands outperformed biaryl phosphanes known to promote the given transformation. Detailed substrate scopes were determined using high-throughput screening technology. Several biaryl phosphorinanes and their corresponding Pd(II) oxidative-addition complexes were extensively characterized using NMR spectroscopy and X-ray crystallography. General observations support that biaryl phosphorinanes promote reductive elimination and form robust catalysts with palladium. In many cases the use of these biaryl phosphorinanes may be advantageous over the use of biaryl phosphanes with respect to lower catalyst loadings, shorter reaction times, and robustness.
Iridium-catalyzed C-H borylation of heteroarenes: Scope, regioselectivity, application to late-stage functionalization, and mechanism
Larsen, Matthew A.,Hartwig, John F.
supporting information, p. 4287 - 4299 (2014/04/03)
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.
