Categories: C=C Bond Formation >
Synthesis of nitro alkenes
By changing reaction conditions (solvent and temperature), it is possible to control the stereochemical outcome of the condensation of aliphatic aldehydes with nitro alkanes obtaining pure (E)- and (Z)-nitro alkenes in high to excellent yields. The role of molecular sieves on the stereochemical control seems crucial in addition to that of piperidine for the synthesis of the Z isomer.
S. Fioravanti, L. Pellacani, P. A. Tardella, M. C. Vergari, Org. Lett., 2008, 10, 1449-1451.
2-Hydroxyethylammonium formate as a cost-effective and task-specific ionic liquid efficiently promotes the condensation of nitroalkanes with various aldehydes to produce β-nitrostyrenes in very good yields at room temperature. This reaction does not involve any hazardous organic solvent and toxic catalyst. The ionic liquid can be recovered and recycled for subsequent reactions.
A. Alizadeh, M. M. Khodaei, A. Eshgi, J. Org. Chem., 2010, 75, 8295-8298.
Radical halo-nitration of alkenes proceeds easily by radical addition of nitrogen dioxide generated by thermal decomposition of iron(III) nitrate nonahydrate and subsequent trapping of the resultant radical by a halogen atom in the presence of a halogen salt. Application of this method to synthesis of nitroalkenes is also described.
T. Taniguchi, T. Fuji, H. Ishibashi, J. Org. Chem., 2010, 75, 8126-8132.