- Visible-light-mediated phosphonylation reaction: formation of phosphonates from alkyl/arylhydrazines and trialkylphosphites using zinc phthalocyanine
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In this work, we developed a ligand- and base-free visible-light-mediated protocol for the photoredox syntheses of arylphosphonates and, for the first time, alkyl phosphonates. Zinc phthalocyanine-photocatalyzed Csp2-P and Csp3-P bond formations were efficiently achieved by reacting aryl/alkylhydrazines with trialkylphosphites in the presence of air serving as an abundant oxidant. The reaction conditions tolerated a wide variety of functional groups.
- Hosseini-Sarvari, Mona,Koohgard, Mehdi
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supporting information
p. 5905 - 5911
(2021/07/12)
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- Cross-Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate-Determining Deprotonation of Bound Hydrazine
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Reported here is the Pd-catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.
- Borate, Kailaskumar,Choi, Kyoungmin,Goetz, Roland,Hartwig, John F.,Shinde, Harish,Wang, Justin Y.,Zuend, Stephan J.
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supporting information
p. 399 - 408
(2020/10/29)
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- One-Pot Synthesis of Indoles and Pyrazoles via Pd-Catalyzed Couplings/Cyclizations Enabled by Aqueous Micellar Catalysis
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An effective one-pot synthesis of either indoles or pyrazoles can be achieved via Pd-catalyzed aminations followed by subsequent cyclizations facilitated by aqueous micellar catalysis. This new technology includes efficient couplings with low loadings of palladium, a more stable source of the required hydrazine moiety, greater atom economy for the initial coupling, and reduced reaction temperatures, all leading to environmentally responsible processes.
- Akporji, Nnamdi,Braga, Felipe C.,Gabriel, Christopher M.,Landstrom, Evan B.,Lee, Nicholas R.,Lipshutz, Bruce H.
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supporting information
(2020/09/02)
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- Palladium-catalyzed cross-coupling of aryl chlorides and tosylates with hydrazine
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Hydrazine is not a problem anymore: The title transformation is the first reaction to yield aryl hydrazines through the cross-coupling of aryl chlorides and tosylates with hydrazine. An appropriately designed palladium catalyst allows this reaction to proceed rapidly under mild conditions, and with excellent chemoselectivity (see scheme; Ad=adamantyl, Ts=4-toluenesulfonyl).
- Lundgren, Rylan J.,Stradiotto, Mark
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supporting information; experimental part
p. 8686 - 8690
(2011/01/08)
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- Thiazolylbenzofuran derivatives and pharmaceutical compositions containing them
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This invention relates to novel thiazolylbenzofuran derivatives of formula (I) wherein R1 is lower alkyl, L is single bond or lower alkylene optionally substituted with aryl, oxo or hydroxy, and Q is a heterocyclic group optionally substituted with one or more suitable substituent(s); or lower alkoxy substituted with aryl which is substituted with one or more suitable substituent(s) and at least one of which is lower alkoxy optionally substituted with cyano, protected carboxy, carboxy, lower alkylene, a heterocyclic group optionally substituted with oxo, or amidino optionally substituted with hydroxy or lower alkoxy, or its salt, which possess activities as leukotriene and SRS-A antagonists or inhibitors.
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