A compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein: R 1 represents independently for each occurrence hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxyl, -(C 1-4 alkylene)-(C 1-4 alkoxyl), cyclopropyl, cyano, chloro, or fluoro; R 2 is hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxyl, cyclopropyl, cyano, chloro, or fluoro; R 3 represents independently for each occurrence hydrogen or C 1-4 alkyl; R 4 represents independently for each occurrence hydrogen, C 1-4 alkyl, or -C R 3; X 1 is one of the following: (a) a carbonyl-containing linker selected from -C N -ψ, -C N (C 1-6 alkylene)-ψ, and -C -(3-6 membered heterocycloalkylene containing at least one ring -N - group)-ψ; where ψ is a bond to A 1; or (b) an amine-containing linker selected from -(C 1-4 alkylene)-N -ψ and -(C 1-4 alkylene)-N -(C 1-4 alkylene)-ψ; A 1 is a cyclic group selected from: • C 3-10 cycloalkyl, phenyl, or 5-6 membered heteroaryl, each of which is substituted by 1 or 2 occurrences of Y 1 and 0, 1, 2, or 3 occurrences of Y 2; and • a bicyclic carbocyclyl that is partially unsaturated or a mono-cyclic or bicyclic heterocyclyl, each of which is substituted by 0, 1, or 2 occurrences of Y 1 and 0, 1, 2, or 3 occurrences of Y 2; Y 1 represents, independently for each occurrence, one of the following: • 2-8 membered heteroalkyl optionally substituted by a 6-10 membered aryl or a 3-10 membered heterocyclyl; • 3-10 membered heterocyclyl, 6-10 membered aryl, C 3-7 cycloalkyl, -O-C 3-7 cycloalkyl, -O-(3-6 membered heterocyclyl), -O-(6-10 membered aryl), or -O-(C 2-6 alkynyl); • C 2-6 alkynyl, -C≡C-(C 1-6 alkylene)-OR 4, -C≡C-(C 1-6 alkylene)-N(R 3) 2, -(C 2-4 alkynylene)-(5-6 membered heteroaryl), or C 2-6 alkenyl; or • halogen or cyano; Y 2 represents, independently for each occurrence, deuterium, C 1-6 alkyl, C 3-6 cycloalkyl, halogen, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, hydroxyl, C 1-6 alkoxyl, cyano, azido, -N(R 3) 2, -(C 1-6 alkylene)-(5-6 membered heterocyclyl), -(C 1-6 alkylene)-CO 2 R 3, or C 1-6 haloalkyl-substituted C 3-6 cycloalkyl; and n is 1, 2, or 3. R 1 represents independently for each occurrence hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxyl, -(C 1-4 alkylene)-(C 1-4 alkoxyl), cyclopropyl, cyano, chloro, or fluoro; R 2 is hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxyl, cyclopropyl, cyano, chloro, or fluoro; R 3 represents independently for each occurrence hydrogen or C 1-4 alkyl; R 4 represents independently for each occurrence hydrogen, C 1-4 alkyl, or -C R 3; X 1 is one of the following: (a) a carbonyl-containing linker selected from -C N -ψ, -C N (C 1-6 alkylene)-ψ, and -C -(3-6 membered heterocycloalkylene containing at least one ring -N - group)-ψ; where ψ is a bond to A 1; or (b) an amine-containing linker selected from -(C 1-4 alkylene)-N -ψ and -(C 1-4 alkylene)-N -(C 1-4 alkylene)-ψ; (a) a carbonyl-containing linker selected from -C N -ψ, -C N (C 1-6 alkylene)-ψ, and -C -(3-6 membered heterocycloalkylene containing at least one ring -N - group)-ψ; where ψ is a bond to A 1; or (b) an amine-containing linker selected from -(C 1-4 alkylene)-N -ψ and -(C 1-4 alkylene)-N -(C 1-4 alkylene)-ψ; A 1 is a cyclic group selected from: • C 3-10 cycloalkyl, phenyl, or 5-6 membered heteroaryl, each of which is substituted by 1 or 2 occurrences of Y 1 and 0, 1, 2, or 3 occurrences of Y 2; and • a bicyclic carbocyclyl that is partially unsaturated or a mono-cyclic or bicyclic heterocyclyl, each of which is substituted by 0, 1, or 2 occurrences of Y 1 and 0, 1, 2, or 3 occurrences of Y 2; • C 3-10 cycloalkyl, phenyl, or 5-6 membered heteroaryl, each of which is substituted by 1 or 2 occurrences of Y 1 and 0, 1, 2, or 3 occurrences of Y 2; and • a bicyclic carbocyclyl that is partially unsaturated or a mono-cyclic or bicyclic heterocyclyl, each of which is substituted by 0, 1, or 2 occurrences of Y 1 and 0, 1, 2, or 3 occurrences of Y 2; Y 1 represents, independently for each occurrence, one of the following: • 2-8 membered heteroalkyl optionally substituted by a 6-10 membered aryl or a 3-10 membered heterocyclyl; • 3-10 membered heterocyclyl, 6-10 membered aryl, C 3-7 cycloalkyl, -O-C 3-7 cycloalkyl, -O-(3-6 membered heterocyclyl), -O-(6-10 membered aryl), or -O-(C 2-6 alkynyl); • C 2-6 alkynyl, -C≡C-(C 1-6 alkylene)-OR 4, -C≡C-(C 1-6 alkylene)-N(R 3) 2, -(C 2-4 alkynylene)-(5-6 membered heteroaryl), or C 2-6 alkenyl; or • halogen or cyano; • 2-8 membered heteroalkyl optionally substituted by a 6-10 membered aryl or a 3-10 membered heterocyclyl; • 3-10 membered heterocyclyl, 6-10 membered aryl, C 3-7 cycloalkyl, -O-C 3-7 cycloalkyl, -O-(3-6 membered heterocyclyl), -O-(6-10 membered aryl), or -O-(C 2-6 alkynyl); • C 2-6 alkynyl, -C≡C-(C 1-6 alkylene)-OR 4, -C≡C-(C 1-6 alkylene)-N(R 3) 2, -(C 2-4 alkynylene)-(5-6 membered heteroaryl), or C 2-6 alkenyl; or • halogen or cyano; Y 2 represents, independently for each occurrence, deuterium, C 1-6 alkyl, C 3-6 cycloalkyl, halogen, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, hydroxyl, C 1-6 alkoxyl, cyano, azido, -N(R 3) 2, -(C 1-6 alkylene)-(5-6 membered heterocyclyl), -(C 1-6 alkylene)-CO 2 R 3, or C 1-6 haloalkyl-substituted C 3-6 cycloalkyl; and n is 1, 2, or 3.