Use of 3-halo-1-azaallylic anions in heterocyclic chemistry

The synthetic potential of lithio 3-halo-1-azaallylic anions as building blocks in organic chemistry and especially in heterocyclic chemistry will be highlighted by the synthesis of functionalized imines, obtained after reaction of 3-halo-1-azaallylic anions with het- eroatom-substituted electrophiles. Thus, the latter generated functionalized imines are suitable building blocks for the synthesis of a whole range of heterocycles and physiologically active compounds, including agrochemicals and pharmaceuticals. 3-Halo-1-azaallylic anions were used in the synthesis of N-alkyl-3,3-dichloroazetidines, 2,3-disubstituted pyrroles, piperidines, 2-substituted pyridines, 2-alkoxytetrahydrofurans,etc., from which a large range of useful and interesting chemicals can be produced, e.g., 2-azetines and 9-alkyl- 2-phenyl-3a-beta,4,6,7,8,9,9a-beta,9b-beta-octahydro-1H-pyrrolo [3,4,h]quinoline-1,3-diones. The utility of the present methodology is demonstrated by the synthesis of the pheromone (S)-manicone, the sulfur-containing flavor compound 2-[(methylthio)methyl ]-2-butenal, and some agrochemical and pharmaceutical compounds.