The actions of estrogens are mediated through the two estrogen receptors, ERα and ERβ. Compounds that interact selectively with ERα or ERβ are of interest because they could be used to explore the biological roles of these ER subtypes and they might be interesting estrogen pharmaceuticals. In a new approach to develop ER subtype-selective ligands, we have embellished the 1, 1-diarylethylene motif, common to many nonsteroidal estrogens, ...