The present invention relates to compounds of formula I: in which n, m, X, Y1, R1, R2, R3, R4 and R5 are defined in the Summary of the Invention; capable of being both potent antagonists and degraders of estrogen receptors. 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 aberrant estrogen receptor activity.