Disclosed are compounds of Formula (I)or stereoisomers or salts thereof, wherein: X1, X2, X3, W, Q1, Q2, and G2 are defined herein. Also disclosed are methods of using such compounds as selective agonists for G protein-coupled receptor S1P1, and pharmaceutical compositions comprising such compounds. These compounds are useful in treating, preventing, or slowing the progression of diseases or disorders in a variety of therapeutic areas, such as autoimmune diseases and vascular disease.