A compound of formula I-b, or a pharmaceutically acceptable salt thereof, wherein: R 1 is selected from one of the following: (a) (b) cyclopentyl, or cyclohexyl; or (c) R 2 is hydrogen, C 1-6 aliphatic, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; or R 1 and R 2 taken together with the atom to which they are attached, forms a 3-7 membered heterocylic ring having 1 nitrogen and 0-3 other heteroatoms independently selected from nitrogen, oxygen, or sulfur; or a 6-10 membered fused or spiro bicyclic heterocylic ring having 1 nitrogen and 0-3 other heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; wherein R 1 or the ring formed by R 1 and R 2 is substituted with R 4 is hydrogen, C 1-6 aliphatic, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; each R 5 is independently C 1-6 alkyl, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; m is 0 or 1. R 1 is selected from one of the following: (a) (b) cyclopentyl, or cyclohexyl; or (c) (a) (b) cyclopentyl, or cyclohexyl; or (c) R 2 is hydrogen, C 1-6 aliphatic, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; or R 1 and R 2 taken together with the atom to which they are attached, forms a 3-7 membered heterocylic ring having 1 nitrogen and 0-3 other heteroatoms independently selected from nitrogen, oxygen, or sulfur; or a 6-10 membered fused or spiro bicyclic heterocylic ring having 1 nitrogen and 0-3 other heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; wherein R 1 or the ring formed by R 1 and R 2 is substituted with R 4 is hydrogen, C 1-6 aliphatic, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; each R 5 is independently C 1-6 alkyl, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; m is 0 or 1. R 4 is hydrogen, C 1-6 aliphatic, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; each R 5 is independently C 1-6 alkyl, C 5-10 aryl, a 3-8 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered heterocylic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; each of which is optionally substituted; m is 0 or 1.