Synthesis of N-Vinylpyrazoles

Аттарян, Оганес С.; Matsoyan, S. G.; Martirosyan, S. S.

doi:10.1007/s10593-005-0170-z

Cited by 15 publications

(3 citation statements)

References 5 publications

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“…Alkynes were purchased from commercial sources and were used as received, except for phenylacetylene, which was distilled under argon and stored over molecular sieves. 1,3-Disubstituted enynes and 1-vinylpyrazole derivatives were synthesized following the procedure described in the literature. Organic solvents were dried by standard procedures and distilled under argon prior to use or obtained oxygen- and water-free from a solvent purification system (Innovative Technologies).…”

Section: Methodsmentioning

confidence: 99%

Rhodium(I)-N-Heterocyclic Carbene Catalyst for Selective Coupling ofN-Vinylpyrazoles with Alkynes via C–H Activation

et al. 2014

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The complex [Rh(μ-Cl)(IPr)(η 2 -coe)] 2 {IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-carbene, coe = cis-cyclooctene} efficiently catalyzes the coupling of alkynes and N-vinylpyrazole via C−H activation, leading to Markovnikovselective butadienylpyrazole derivatives under mild conditions. A straightforward approach to cross-conjugated acyclic trienes is also operative through a one-pot alkyne dimerizationhydrovinylation tandem reaction. The proposed mechanism involves C−H activation of vinylpyrazole directed by nitrogen coordination to the metallic center. Subsequent alkyne coordination, insertion, and reductive elimination steps lead to the coupling products.Several key intermediates participating in the catalytic cycle have been detected and characterized, including a κ-N, η 2 -CC coordinated vinylpyrazole complex and a Rh IIIhydride-alkenyl species resulting from the C−H activation of the vinylpyrazole

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Section: Methodsmentioning

confidence: 99%

Rhodium(I)-N-Heterocyclic Carbene Catalyst for Selective Coupling ofN-Vinylpyrazoles with Alkynes via C–H Activation

et al. 2014

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“…The wasteful production of side product 9 , as well as the use of K 2 CO 3 and DMF in the first generation process, led to multiple processing steps with extensive workup, solvent exchanges, and the use of multiple reactors. Therefore, a new stage 1 process using phase transfer catalysis (PTC) in water was investigated for the synthesis of 7 . Initial experiments to condense 5 with 1,2-dibromoethane in mixtures of toluene and aqueous base in the presence of catalytic tricaprylylmethylammonium chloride (Aliquat 336) at 60 °C resulted in 50% conversion to 7 .…”

Section: Second-generation Synthesismentioning

confidence: 99%

Development of an Efficient, Safe, and Environmentally Friendly Process for the Manufacture of GDC-0084

Stumpf

McClory

Yajima

et al. 2016

Org. Process Res. Dev.

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An improved, efficient process with a significantly reduced process mass intensity (PMI) led to the multikilogram synthesis of a brain penetrant PI3K inhibitor GDC-0084. Highlights of the synthesis include a phase transfer catalyzed annulation in water, an efficient Suzuki-Miyaura cross-coupling of a chloropyrimidine with an arylboronic acid using a low palladium catalyst loading, and the development of a controlled crystallization to provide the API. The process delivered GDC-0084 with low levels of both impurities and residual metals.

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“…As a result, deprotonation was hindered and the base was consumed in elimination of dichloroethane. It must also be mentioned that a 5-to 7-folds excess of dichloroethane was necessary to obtain optimal yields on alkylation of compounds 301-303 [101] (Figure 109). ethylfuran 310 with dodecyl bromide without solvent using (KOH/aliquat) as a catalyst, while alkylation of furfuryl alcohol 312 with 1,12-dibromododecane under the same PTC conditions produced the corresponding furanic diether 313 [102] (Figure 110).…”

Section: Journal Of Chemistrymentioning

confidence: 99%

Synthesis and Reactions of Five-Membered Heterocycles Using Phase Transfer Catalyst (PTC) Techniques

El-Sayed

Allah

El‐Saghier

et al. 2014

Journal of Chemistry

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Phase transfer catalysts (PTCs) have been widely used for the synthesis of organic compounds particularly in both liquid-liquid and solid-liquid heterogeneous reaction mixtures. They are known to accelerate reaction rates by facilitating formation of interphase transfer of species and making reactions between reagents in two immiscible phases possible. Application of PTC instead of traditional technologies for industrial processes of organic synthesis provides substantial benefits for the environment. On the basis of numerous reports it is evident that phase-transfer catalysis is the most efficient way for generation and reactions of many active intermediates. In this review we report various uses of PTC in syntheses and reactions of five-membered heterocycles compounds and their multifused rings.

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Synthesis of N-Vinylpyrazoles

Cited by 15 publications

References 5 publications

Rhodium(I)-N-Heterocyclic Carbene Catalyst for Selective Coupling ofN-Vinylpyrazoles with Alkynes via C–H Activation

Rhodium(I)-N-Heterocyclic Carbene Catalyst for Selective Coupling ofN-Vinylpyrazoles with Alkynes via C–H Activation

Development of an Efficient, Safe, and Environmentally Friendly Process for the Manufacture of GDC-0084

Synthesis and Reactions of Five-Membered Heterocycles Using Phase Transfer Catalyst (PTC) Techniques

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