- Transformations of Aryl Ketones via Ligand-Promoted C?C Bond Activation
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The coupling of aromatic electrophiles (aryl halides, aryl ethers, aryl acids, aryl nitriles etc.) with nucleophiles is a core methodology for the synthesis of aryl compounds. Transformations of aryl ketones in an analogous manner via carbon–carbon bond activation could greatly expand the toolbox for the synthesis of aryl compounds due to the abundance of aryl ketones. An exploratory study of this approach is typically based on carbon–carbon cleavage triggered by ring-strain release and chelation assistance, and the products are also limited to a specific structural motif. Here we report a ligand-promoted β-carbon elimination strategy to activate the carbon–carbon bonds, which results in a range of transformations of aryl ketones, leading to useful aryl borates, and also to biaryls, aryl nitriles, and aryl alkenes. The use of a pyridine-oxazoline ligand is crucial for this catalytic transformation. A gram-scale borylation reaction of an aryl ketone via a simple one-pot operation is reported. The potential utility of this strategy is also demonstrated by the late-stage diversification of drug molecules probenecid, adapalene, and desoxyestrone, the fragrance tonalid as well as the natural product apocynin.
- Dai, Hui-Xiong,Li, Hanyuan,Li, Ling-Jun,Liu, Qi-Sheng,Ma, Biao,Wang, Mei-Ling,Wang, Xing,Wang, Zhen-Yu,Xu, Hui
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p. 14388 - 14393
(2020/07/06)
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- Meta-Selective C-H Borylation of Benzamides and Pyridines by an Iridium-Lewis Acid Bifunctional Catalyst
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We report herein the iridium-catalyzed meta-selective C-H borylation of benzamides by using a newly designed 2,2′-bipyridine (bpy) ligand bearing an alkylaluminum biphenoxide moiety. We also demonstrate the iridium-catalyzed C3-selective C-H borylation of pyridine with a 1,10-phenanthroline (Phen) ligand bearing an alkylborane moiety. It is proposed that the Lewis acid-base interaction between the Lewis acid moiety and the aminocarbonyl group or the sp2-hybridized nitrogen atom accelerates the reaction and controls the site-selectivity.
- Yang, Lichen,Uemura, Nao,Nakao, Yoshiaki
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supporting information
p. 7972 - 7979
(2019/05/22)
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- Development of matrix metalloproteinase-13 inhibitors – A structure-activity/structure-property relationship study
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A structure-activity/structure-property relationship study based on the physicochemical as well as in vitro pharmacokinetic properties of a first generation matrix metalloproteinase (MMP)-13 inhibitor (2) was undertaken. After systematic variation of inhi
- Fuerst, Rita,Yong Choi, Jun,Knapinska, Anna M.,Smith, Lyndsay,Cameron, Michael D.,Ruiz, Claudia,Fields, Gregg B.,Roush, William R.
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supporting information
p. 4984 - 4995
(2018/09/27)
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- BASE METAL CATALYZED BORYLATION OF ARENES AND AROMMATIC HETEROCYCLES
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In one aspect, cobalt complexes are described herein. In some embodiments, such cobalt complexes employ bis(phosphine) or bis(imine) ligand and are operable as catalysts for borylation of arenes and aromatic heterocycles.
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Page/Page column 34
(2015/06/25)
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- Iridium-catalyzed C-H borylation of pyridines
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The iridium-catalysed C-H borylation is a valuable and attractive method for the preparation of aryl and heteroaryl boronates. However, application of this methodology for the preparation of pyridyl and related azinyl boronates can be challenged by low reactivity and propensity for rapid protodeborylation, particularly for a boronate ester ortho to the azinyl nitrogen. Competition experiments have revealed that the low reactivity is due to inhibition of the active catalyst through coordination of the azinyl nitrogen lone pair at the vacant site on the iridium. This effect can be overcome through the incorporation of a substituent at C-2. Moreover, when this is sufficiently electron-withdrawing protodeborylation is sufficiently slowed to permit isolation and purification of the C-6 boronate ester. Following functionalization, reduction of the directing C-2 substituent provides the product arising from formal ortho borylation of an unhindered pyridine ring. This journal is the Partner Organisations 2014.
- Sadler, Scott A.,Tajuddin, Hazmi,Mkhalid, Ibraheem A. I.,Batsanov, Andrei S.,Albesa-Jove, David,Cheung, Man Sing,Maxwell, Aoife C.,Shukla, Lena,Roberts, Bryan,Blakemore, David C.,Lin, Zhenyang,Marder, Todd B.,Steel, Patrick G.
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supporting information
p. 7318 - 7327
(2014/11/07)
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- N-Acyl-N'-(pyridin-2-yl) Ureas and Analogs Exhibiting Anti-Cancer and Anti-Proliferative Activities
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Described are compounds of Formula I which find utility in the treatment of cancer, autoimmune diseases and metabolic bone disorders through inhibition of c-FMS (CSF-1R), c-KIT, and/or PDGFR kinases. These compounds also find utility in the treatment of other mammalian diseases mediated by c-FMS, c-KIT, or PDGFR kinases.
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Paragraph 0403
(2014/09/30)
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- Cobalt-catalyzed C-H borylation
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A family of pincer-ligated cobalt complexes has been synthesized and are active for the catalytic C-H borylation of heterocycles and arenes. The cobalt catalysts operate with high activity and under mild conditions and do not require excess borane reagents. Up to 5000 turnovers for methyl furan-2-carboxylate have been observed at ambient temperature with 0.02 mol % catalyst loadings. A catalytic cycle that relies on a cobalt(I)-(III) redox couple is proposed.
- Obligacion, Jennifer V.,Semproni, Scott P.,Chirik, Paul J.
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supporting information
p. 4133 - 4136
(2014/04/03)
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- Synthesis of biaryls through a one-pot tandem borylation/Suzuki-Miyaura cross-coupling reaction catalyzed by a palladacycle
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The tricyclohexylphosphane adduct of cyclopalladated ferrocenylimine I exhibited high catalytic activity in the one-pot borylation/Suzuki-Miyaura coupling (BSC) reaction with low catalyst loading (2 mol-%). Various biaryls were obtained in good to excellent yields for 37 examples. This process was applied to aryl and heteroaryl halides (Br and Cl) containing a variety of functional groups and did not require an excess amount of phosphane ligand and the addition of the palladium catalyst in the second step. Cyclopalladated ferrocenylimine I exhibited high catalytic activity in the borylation/Suzuki- Miyaura coupling (BSC) reaction with low catalyst loading. Various unsymmetrical biaryls were obtained ingood to excellent yields in one pot. This protocol was applied to aryl and heteroaryl halides (Br and Cl) containing a variety of functional groups without adding catalyst in the second step. Copyright
- Wang, Lianhui,Cui, Xiuling,Li, Jingya,Wu, Yusheng,Zhu, Zhiwu,Wu, Yangjie
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experimental part
p. 595 - 603
(2012/03/09)
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- CHEMICAL COMPOUNDS
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The invention relates to chemical compounds, or pharmaceutically acceptable salts thereof, of the formula (I): which possess B-Raf inhibitory activity and are accordingly useful for their anti-cancer activity and thus in methods of treatment of the human or animal body. The invention also relates to processes for the manufacture of said chemical compounds, to pharmaceutical compositions containing them and to their use in the manufacture of medicaments of use in the production of an anti-cancer effect in a warm-blooded animal such as man.
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Page/Page column 42-43
(2008/06/13)
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- THIOPYRAN COMPOUNDS AS INHIBITORS OF MMP
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A compound of formula (I) in which R is lower alkyl, halogen, optionally substituted heterocyclic group or optionally substituted aryl, R is carboxy, protected carboxy or amidated carboxy, Ar is optionally substituted aryl or optionally substituted heterocyclic group, A is lower alkylene, X is oxa or a single bond, Y is thia, sulfinyl or sulfonyl, Z is methylene, thia, sulfinyl or sulfonyl, m and n are each an integer of 0 to 6, and 1/=m+n/=6, or its salt, which is useful as an inhibitor of matrix metalloproteinases (MMP) or tumor necrosis factor alpha (TNF alpha ).
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