The present invention relates to compounds of formula I: in which Y1, Y2, Y3, Y4 R1, R2, R4a, R4b, R5a, R5b, R6a and R6b are defined in the Summary of the Invention; capable of inhibiting the activity of SHP2. The invention further provides a process for the preparation of compounds of the invention, pharmaceutical preparations comprising such compounds and methods of using such compounds and compositions in the management of diseases or disorders associated with the aberrant activity of SHP2.