N,N-Dimethylformamide, 99%, Thermo Scientific Chemicals

General References:

1. Dipolar aprotic solvent, in which anions have enhanced nucleophilicity, compare Dimethyl sulfoxide, A13280. Effective solvent for a vast range of reactions.
2. CAUTION! Thermal runaway reactions can occur with NaH; see Sodium hydride, 13431.
3. In combination with POCl₃, (COCl)₂, etc., generates an iminium chloride intermediate for the formylation of reactive aromatic nuclei by the Vilsmeier reaction:
4. Compare also N-Methyl formanilide, A11829, and preformed Vilsmeier reagent (Chloromethyl ene) dimethyl ammonium chloride, B24172. Monograph: Synthesis Using Vilsmeier Reagents, C. M. Marson, P. R. Giles, CRC Press, Boca Raton, FL (1994). Formylation can be extended to less active substrates, e.g. acenaphthene or mesitylene, with the DMF-triflic anhydride reagent: J. Chem. Soc., Chem. Commun., 1571 (1990). Under Vilsmeier conditions, electron-rich alkenes can be converted to ɑß-unsaturated aldehydes; see, e.g.: Synthesis, 752 (1976); and ketones to ß-chloroenals: Synthesis, 496 (1985); Org. Synth. Coll., 5, 215 (1973).
5. Vilsmeier conditions also promote dehydrations, e.g. in cyclodehydration of hydroxyphenols to give cyclic ethers, as an efficient alternative to the Mitsunobu reaction: J. Chem. Soc., Perkin 1, 2249 (1996); J. Org. Chem., 59, 4346 (1994):
6. DMF can also be used for formylation with alkyllithium or Grignard reagents: Synthesis, 228 (1984).
7. In aqueous DMF, tosylate esters undergo formolysis to formate esters: Synth. Commun., 26, 1031 (1996).
8. For the free-radical formylation of perfluoroalkyl iodides, see Zinc-copper couple, L09811.