- Continuous Platform to Generate Nitroalkanes On-Demand (in Situ) Using Peracetic Acid-Mediated Oxidation in a PFA Pipes-in-Series Reactor
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The synthetic utility of the aza-Henry reaction can be diminished on scale by potential hazards associated with the use of peracid to prepare nitroalkane substrates and the nitroalkanes themselves. In response, a continuous and scalable chemistry platform to prepare aliphatic nitroalkanes on-demand using the oxidation of oximes with peracetic acid and direct reaction of the nitroalkane intermediate in an aza-Henry reaction is reported. A uniquely designed pipes-in-series plug-flow tube reactor addresses a range of process challenges, including stability and safe handling of peroxides and nitroalkanes. The subsequent continuous extraction generates a solution of purified nitroalkane, which can be directly used in the following enantioselective aza-Henry chemistry to furnish valuable chiral diamine precursors with high selectivity, thus completely avoiding isolation of the potentially unsafe low-molecular-weight nitroalkane intermediate. A continuous campaign (16 h) established that these conditions were effective in processing 100 g of the oxime and furnishing 1.4 L of nitroalkane solution.
- Tsukanov, Sergey V.,Johnson, Martin D.,May, Scott A.,Kolis, Stanley P.,Yates, Matthew H.,Johnston, Jeffrey N.
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supporting information
p. 971 - 977
(2018/08/28)
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- Green synthesis method for preparing nitroalkanes by oxime oxidation
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The invention belongs to the field of organic chemical industries, and provides a green synthesis method for preparing nitroalkanes by oxime oxidation. At the temperature of 55 to 120 DEG C and under the pressure of 0 to 1.0 MPa, oxime, a solvent and hydrogen peroxide are reacted for 20 to 200min in the presence of certain amounts of nanoporous skeleton metal hybrid catalysts and cocatalysts, a reaction liquid is subjected to membrane separation, the catalysts can be repeatedly used for more than 7 times, and distilled to obtain nitroalkane products, the purity of the products is not less than 99%, and the yield of the products is not less than 95%. Furthermore, the green synthesis method for preparing nitroalkanes by the oxime oxidation disclosed by the invention is a green synthesis method of nitroalkanes, and suitable for large-scale industrialized production.
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Paragraph 0061; 0062
(2017/08/29)
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- Catalytic Enantioselective Desymmetrization of Norbornenoquinones via C(sp2)-H Alkylation
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The enantioselective Diels-Alder (DA) reaction with monosubstituted p-benzoquinones is an unmet challenge. A new approach for the enantioselective synthesis of monosubstituted quinone-DA adducts is presented based on C(sp2)-H alkylative desymmetrization of meso-DA adducts. Catalyzed by a tertiary amino-thiourea derivative, this reaction utilizes nitroalkanes as the alkylating agents and generates densely functionalized products bearing at least four contiguous stereogenic centers remote from the reaction site with excellent enantioselectivities.
- Sarkar, Rahul,Mukherjee, Santanu
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supporting information
p. 6160 - 6163
(2016/12/09)
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- Synthesis of functionalized nitroalkanes by oxidation of oximes with urea-hydrogen peroxide complex and trifluoroacetic anhydride
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Reaction of urea-hydrogen peroxide complex with trifluoroacetic anhydride in acetonitrile at 0°C affords in a safe and easy fashion anhydrous solutions of peroxytrifluoroacetic acid. These can be used to oxidize aldoximes to nitroalkanes in good yields. Ketoximes fail to react in these conditions and are cleaved to the parent carbonyl compounds.
- Ballini, Roberto,Marcantoni, Enrico,Petrini, Marino
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p. 4835 - 4838
(2007/10/02)
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