DTBB-CATALYZED LITHIATION OF 2,3-DICHLOROPROPENE AND RELATED CHLOROAMINES - SYNTHETIC APPLICATIONS

The reaction of 2,3-dichloropropene (1) and different carbonyl compounds (2) with an excess of lithium powder (1:7 molar ratio) in the presence of a catalytic amount of DTBB (5 mol %) in THF at 0 degrees C leads,after hydrolysis with water, to the corresponding methylenic 1,4-diols 3 in a Barbier-type process. The cyclisation of diols 3 under acidic conditions (hydrochloric or phosphoric acid) yields the corresponding substituted methylenic tetrahydrofurans 4. Finally, 2,3-dichloropropene (1) is converted into the corresponding allylic chloroamines 5 and then submitted to the tandem naphthalene-catalysed lithiation-dB reaction with different electrophiles affording the corresponding functionalised amines 7. The last process fails for oxygen- or sulfur-containing chloroallylic materials 8.