Coupling reaction in catalytic decomposition of cyclohexyl hydroperoxide

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.

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Ferromagnetic Chain Based on Verdazyl-Nitroxide Diradical

10.26434/chemrxiv.12367334.v1 ◽

2020 ◽

Author(s):

Evgeny Tretyakov ◽

Svetlana Zhivetyeva ◽

Pavel Petunin ◽

Dmitry Gorbunov ◽

Nina Gritsan ◽

...

Keyword(s):

Coupling Reaction ◽

Cross Coupling ◽

Ferromagnetic Coupling ◽

Nitronyl Nitroxide ◽

Triplet Ground State ◽

One Dimensional ◽

Cross Coupling Reaction ◽

Palladium Catalyzed ◽

Ferromagnetic Chain ◽

High Yields

Verdazyl-nitroxide diradicals were synthesized using the palladium-catalyzed cross-coupling reaction of the corresponding iodoverdazyls with a nitronyl nitroxide-2-ide gold(I) complex with high yields (up to 82%). The synthesized diradicals were found to be highly thermally stable and have a singlet (DEST » -64 cm–1) or triplet ground state (DEST ³ 25 and 100 cm–1), depending on which canonical hydrocarbon diradical type they belong to. Upon crystallization, triplet diradicals form unique one-dimensional (1D) spin S = 1 chains of organic diradicals with intrachain ferromagnetic coupling of J′/kB from 3 to 6 K.

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An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

10.26434/chemrxiv.12582284.v1 ◽

2020 ◽

Author(s):

Chet Tyrol ◽

Nang Yone ◽

Connor Gallin ◽

Jeffery Byers

Keyword(s):

Coupling Reaction ◽

Cross Coupling ◽

Coupling Reactions ◽

Radical Intermediates ◽

Cross Coupling Reactions ◽

Cross Coupling Reaction ◽

Boronic Esters ◽

Carbon Centered Radical ◽

Iron Based ◽

High Yields

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.

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Ni(0)-Catalyzed α-Allylic Alkylation of Regular Ketones with 1,3-Dienes under pH and Redox-neutral Conditions

10.26434/chemrxiv.7072646.v3 ◽

2019 ◽

Cited By ~ 1

Author(s):

Tiantian Chen ◽

Yang Yang ◽

Liyu Xie ◽

Haijian Yang ◽

Guangbin Dong ◽

...

Keyword(s):

Oxidative Addition ◽

Coupling Reaction ◽

Cross Coupling ◽

Dual Role ◽

Allylic Alkylation ◽

Cross Coupling Reaction ◽

Neutral Conditions

We report a Ni(0)-catalyzed cross coupling reaction between simple ketones and 1,3-dienes. A variety of a-allylic alkylation products were formed in an 1,2-addition manner with excellent regioselectivity. Water was found to significantly accelerate this transformation. A HO-Ni-H species generated from oxidative addition of Ni(0) to H2O is proposed to play a “dual role” in activating both the ketone and the diene substrate.

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