- Desulfonative Suzuki–Miyaura Coupling of Sulfonyl Fluorides
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Sulfonyl fluorides have emerged as powerful “click” electrophiles to access sulfonylated derivatives. Yet, they are relatively inert towards C?C bond forming transformations, notably under transition-metal catalysis. Here, we describe conditions under which aryl sulfonyl fluorides act as electrophiles for the Pd-catalyzed Suzuki–Miyaura cross-coupling. This desulfonative cross-coupling occurs selectively in the absence of base and, unusually, even in the presence of strong acids. Divergent one-step syntheses of two analogues of bioactive compounds showcase the expanded reactivity of sulfonyl fluorides to encompass both S?Nu and C?C bond formation. Mechanistic experiments and DFT calculations suggest oxidative addition occurs at the C?S bond followed by desulfonation to form a Pd-F intermediate that facilitates transmetalation.
- Bahadori, Maryam,Brykczyńska, Daria,Chatelain, Paul,Moran, Joseph,Muller, Cyprien,Rowley, Christopher N.,Sau, Abhijit
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p. 25307 - 25312
(2021/10/25)
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- Regioselective Cyanation of Six-Membered N-Heteroaromatic Compounds Under Metal-, Activator-, Base- and Solvent-Free Conditions
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A regioselective cyanation of heteroaromatic N-oxides with trimethylsilyl cyanide has been developed to obtain 2-substituted N-heteroaromatic nitrile without the requirement of any external activator-, metal-, base-, and solvent. The present protocol is a straightforward, one-pot heteroaromatic C?H cyanation process, and proceeds smoothly in conventional heating but also under microwave irradiation with shorter reaction times. This approach now allows access to a broad class of quinoline N-oxides and other heteroarene N-oxides with high to good yields and can also be scaled up to obtain gram quantities. Further application of this process was observed and utilized in late-stage cyanation of the anti-malarial drug quinine as well as transformation of the 2-cyanoazines to a series of biologically important molecules. Based on the experimental observations, a plausible mechanism has also been proposed highlighting the dual role of trimethylsilyl cyanide as a nitrile source and as an activating agent. (Figure presented.).
- Sarmah, Bikash Kumar,Konwar, Monuranjan,Bhattacharyya, Dipanjan,Adhikari, Priyanka,Das, Animesh
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p. 5616 - 5625
(2019/11/22)
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- Diversification of 6-bromo-2-substituted Pyridine Derivatives via Suzuki-Miyaura Cross-Coupling
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The functionalized pyridine ring is a ubiquitous moiety in numerous research areas including materials, natural products, as well as agrochemicals and is a strategic synthon for heteroaromatic synthetic method development. Pyridinyl ligand scaffolds are also frequently incorporated into the study of metal complexes for pharmaceutical applications or separation science. Convergent access to advanced synthons is critical to experimentally defining structure activity relationships and improvement of molecular performance in the aforementioned areas. The current work describes an efficient catalyst/ligand combination for accessing 2-acetyl- and 2-procarbonyl substituted pyridines via Suzuki-Miyaura cross-coupling with various organotrifluoroborates. Twenty examples are described with carbonyl and procarbonyl functional groups which afford subsequent access to diversified unsymmetric ketones. Substrate scope and limitation in addition to?a scale up experiment are reported.
- Lambert, Abigail E.,Carrick, Jesse D.
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p. 1232 - 1239
(2018/04/14)
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- C?H Cyanation of 6-Ring N-Containing Heteroaromatics
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Heteroaromatic nitriles are important compounds in drug discovery, both for their prevalence in the clinic and due to the diverse range of transformations they can undergo. As such, efficient and reliable methods to access them have the potential for far-reaching impact across synthetic chemistry and the biomedical sciences. Herein, we report an approach to heteroaromatic C?H cyanation through triflic anhydride activation, nucleophilic addition of cyanide, followed by elimination of trifluoromethanesulfinate to regenerate the cyanated heteroaromatic ring. This one-pot protocol is simple to perform, is applicable to a broad range of decorated 6-ring N-containing heterocycles, and has been shown to be suitable for late-stage functionalization of complex drug-like architectures.
- Elbert, Bryony L.,Farley, Alistair J. M.,Gorman, Timothy W.,Johnson, Tarn C.,Genicot, Christophe,Lallemand, Bénédicte,Pasau, Patrick,Flasz, Jakub,Castro, José L.,MacCoss, Malcolm,Paton, Robert S.,Schofield, Christopher J.,Smith, Martin D.,Willis, Michael C.,Dixon, Darren J.
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supporting information
p. 14733 - 14737
(2017/10/07)
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- C-H FLUORINATION OF HETEROCYCLES WITH SILVER (II) FLUORIDE
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The present invention provides compositions and methods for the selective C-H fluorination of nitrogen-containing heteroarenes with AgF2, which has previously been considered too reactive for practical, selective C-H fluorination. Fluorinated heteroarenes are prevalent in numerous pharmaceuticals, agrochemicals and materials. However, the reactions used to introduce fluorine into these molecules require pre-functionalized substrates or the use of F2 gas. The present invention provides a mild and general method for the C-H fluorination of nitrogen-containing heteroarene compounds to 2-fluoro-heteroarenes with commercially available AgF2. In various embodiments, these reactions occur at ambient temperature within one hour and occur with exclusive selectivity for fluorination at the 2-position. Exemplary reaction conditions are effective for fluorinating diazine heteroarenes to form a single fluorinated isomer.
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- Synthesis and late-stage functionalization of complex molecules through C-H fluorination and nucleophilic aromatic substitution
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We report the late-stage functionalization of multisubstituted pyridines and diazines at the position α to nitrogen. By this process, a series of functional groups and substituents bound to the ring through nitrogen, oxygen, sulfur, or carbon are installed. This functionalization is accomplished by a combination of fluorination and nucleophilic aromatic substitution of the installed fluoride. A diverse array of functionalities can be installed because of the mild reaction conditions revealed for nucleophilic aromatic substitutions (SNAr) of the 2-fluoroheteroarenes. An evaluation of the rates for substitution versus the rates for competitive processes provides a framework for planning this functionalization sequence. This process is illustrated by the modification of a series of medicinally important compounds, as well as the increase in efficiency of synthesis of several existing pharmaceuticals.
- Fier, Patrick S.,Hartwig, John F.
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p. 10139 - 10147
(2014/08/05)
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- 2-AMINOCARBONYL-PYRIDINE DERIVATIVES
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The present invention relates to 2-aminocarbonyl-pyridine derivatives and their use as P2Yi2 receptor antagonists in the treatment and/or prevention of peripheral vascular, of visceral-, hepatic- and renal-vascular, of cardiovascular and of cerebrovascular diseases or conditions associated with platelet aggregation, including thrombosis in humans and other mammals.
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Page/Page column 109
(2008/06/13)
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- 1,3-BENZOTHIAZINONE DERIVATIVES AND USE THEREOF
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This invention provides a compound represented by the formula (I) :wherein R1 is a hydrogen atom, a halogen atom, hydroxy, nitro, optionally halogenated alkyl, alkoxy optionally having substituents, acyl or amino optionally having substituents;R2 is pyridyl, furyl, thienyl, pyrrolyl, quinolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, tetrahydroquinolyl or thiazolyl, each of which may have substituents;n is 1 or 2; or a salt. And this invention provides a safe pharmaceutical comprising the compound of the formula (I) , which has an excellent apoptosis inhibitory effect and MIF binding effect, for preventing and/or treating heart disease, nervous degenerative disease, cerebrovascular disease, central nervous infectious disease, traumatorathy, demyelinating disease, bone and articular disease, kidney disease, liver disease, osteomyelodysplasia, AIDS, cancer, and the like.
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- A long-range chiral relay via tertiary amide group in asymmetric catalysis: new amino acid-derived N,P-ligands for copper-catalysed conjugate addition.
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New N,P-ligands 4-6, derived from valinol and prolinol, respectively, have been developed for the asymmetric, copper(I)-catalysed conjugate addition of diethylzinc to unsaturated ketones; the tertiary amide group has been shown to effectively relay the chiral information from the ligand backbone to the active centre.
- Malkov, Andrei V,Hand, John B,Kocovsky, Pavel
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p. 1948 - 1949
(2007/10/03)
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