Novel domino reaction of N-(cyanomethyl)-5,10-dihydro[1]benzosilano[3,2-c] pyridinium salts with salicylaldehydes

The synthesis of benzosilanochromenoimidazopyridines was accomplished by a domino reaction of 5,5-dimethyl-10-oxo- and 10-hydroxy-10- allyldihydrobenzosilanopyridinium N-cyanomethyl salts with salicyl- and 5-bromosalicylaldehydes. It was found that in the case of the 10-allyl-10-hydroxy-dihydrobenzosilanopyridinium salts the reaction occurred at both α-positions of the pyridine fragment to form a mixture of the isomeric benzosilano[3,2-c]- and benzosilano[2,3-d]chromenoimidazo-pyridines. © 2013 Springer Science+Business Media New York.