Organozinc reagents diastereoselective addition reactions

Amuilations of pyridinium- and quinolinium-salts however have not been reported so far. From the addition reactions of C-nucIeophiles like Grignard, organozinc and organotin reagents to pyridinium- and quinolinium-salts have been reported to be valuable methods for the construction of substituted dihydropyridine [4a-4d] and dihydroquinoline-derivatives [4d-4e] results of our studies in the field of benzothiopyrylium-salts [5] we concluded that the sequential intermolecular 1,2-addition/intramolecular 1,4-addition of 4-silyloxyquinolinium-salts 1 with 2-silyloxy-l,3-butadienes 2 might be useful for the diastereoselective preparation of annulated quinolones 3. 

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