- Copper-Catalyzed Oxidation of Hydrazones to Diazo Compounds Using Oxygen as the Terminal Oxidant
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A mild method for accessing diazo compounds via aerobic oxidation of hydrazones is described. This catalytic transformation employs a Cu(OAc)2/pyridine catalyst and molecular oxygen from ambient air as the terminal oxidant, generating water as the sole byproduct and affording the desired diazo compounds within minutes at room temperature. A broad array of electronically diverse aryldiazo esters, ketones, and amides can be accessed. Pyridine dramatically enhances the rate of the reaction by solubilizing the copper catalyst and serving as the Br?nsted base in the turnover-limiting proton-coupled oxidation of hydrazone by copper(II). Insights gained from mechanistic studies led to expansion of the scope of this method to include diaryl hydrazones, delivering diaryl diazomethane derivatives, which cannot be accessed via established diazo transfer methods. The products of this method may be employed in rhodium carbene catalysis without isolation of the diazo intermediate to afford cyclopropane products in good yield with high enantioselectivity.
- Liu, Wenbin,Twilton, Jack,Wei, Bo,Lee, Maizie,Hopkins, Melissa N.,Bacsa, John,Stahl, Shannon S.,Davies, Huw M. L.
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p. 2676 - 2683
(2021/03/03)
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- SMALL MOLECULE LFA-1 INHIBITORS
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The present invention relates to novel compounds which are capable of inhibiting the interaction of LFA-1 with its counter ligands.
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Page/Page column 124
(2016/01/01)
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- Substituted diaryldiazomethanes and diazofluorenes: Structure, reactivity and stability
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The synthesis of several substituted diaryldiazomethanes and diazofluorenes, and an assessment of their structure, reactivity and stability, is reported.
- Davis, Philip J.,Harris, Lawrence,Karim, Aman,Thompson, Amber L.,Gilpin, Martin,Moloney, Mark G.,Pound, Matthew J.,Thompson, Claire
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supporting information; experimental part
p. 1553 - 1556
(2011/04/26)
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- + HYDROGEN BOND IN ORGANIC RADICAL SOLID
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Reaction of m- or p-pyridyl nitronyl nitroxide (m- or p-PYNN) with HBr gas gave a 2:1 complex between them.The IR spectra of (m- and p-PYNN)2HBr indicates an intermolecular + hydrogen bond between two pyridyl rings. (m-PYNN)2HBr shows ferr
- Okuno, Tsunehisa,Otsuka, Takeo,Awaga, Kunio
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