Compounds which are pyrrolo[2,3-b]pyridine derivatives or pharmaceutically acceptable salts thereof, their preparation process and pharmaceutical compositions comprising them are disclosed; these compounds are useful in the treatment of diseases caused by and/or associated with an altered protein kinase activity such as cancer, cell proliferative disorders, Alzheimer's disease, viral infections, auto-immune diseases and neurodegenerative disorders; also disclosed is a process under SPS conditions for preparing the compounds of the invention and chemical libraries comprising a plurality of them.