A compound of Formula I or a pharmaceutically acceptable salt thereof: wherein each of R1-R5 is optionally substituted and independently chosen from -H, halo, alkyl, alkoxy, cycloalkoxy, haloalkyl, haloalkoxy, -L-aryl, -L-heteroaryl, -L-heterocyclyl, -L-carbocyclyl, acylamino, acyloxy, alkylthio, cycloalkylthio, alkynyl, amino, aryl, arylalkyl, arylalkenyl, arylalkynyl, arylalkoxy, aryloxy, arylthio, heteroarylthio, cyano, cyanato, haloaryl, hydroxyl, heteroaryloxy, heteroarylalkoxy, isocyanato, isothiocyanato, nitro, sulfinyl, sulfonyl, sulfonamide, thiocarbonyl, thiocyanato, trihalomethanesulfonamido, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, and C-amido; R6 is chosen from -H and alkyl; R7 is chosen from -H, alkyl, and cycloalkyl; R8 is chosen from -C(=O)NR x R y and -C(=O)R z; R x when present is chosen from -H, alkyl, alkynyl, alkenyl, -L-carbocyclyl, and -L-heterocyclyl, all of which are optionally substituted; R y when present is chosen from -H, alkyl, alkynyl, alkenyl, -L-carbocyclyl, -L-aryl, and -L-heterocyclyl, all of which are optionally substituted; R z when present is chosen from -H, alkoxy, -L-carbocyclyl, -L-heterocyclyl,and -L-aryl, wherein the aryl, heterocyclyl, or carbocyclyl is optionally substituted; each L can be saturated, partially saturated, or unsaturated, and is independently chosen from -(CH 2) n -(CH 2) n -, -(CH 2) n C(=O)(CH 2) n -, -(CH 2) n C(=O)NH(CH 2) n -, -(CH 2) n NHC(=O)O(CH 2) n -, -(CH 2) n NHC(=O)NH(CH 2) n -, -(CH 2) n NHC(=S)S(CH 2) n -,-(CH 2) n OC(=O)S(CH 2) n -, -(CH 2) n NH(CH 2) n -, -(CH 2) n O(CH 2) n -, -(CH 2) n S(CH 2) n -, and -(CH 2) n NHC(=S)NH(CH 2) n -, where each n is independently chosen from 0, 1, 2, 3, 4, 5, 6, 7, and 8; and wherein optionally substituted refers to zero or 1 to 4 optional substituents independently chosen from acylamino, acyloxy, alkenyl, alkoxy, cycloalkoxy, alkyl, alkylthio, cycloalkylthio, alkynyl, amino, aryl, arylalkyl, arylalkenyl, arylalkynyl, arylalkoxy, aryloxy, arylthio, heteroarylthio, carbocyclyl, cyano, cyanato, halo, haloalkyl, haloaryl, hydroxyl, heteroaryl, heteroaryloxy, heterocyclyl, heteroarylalkoxy, isocyanato, isothiocyanato, nitro, sulfinyl, sulfonyl, sulfonamide, thiocarbonyl, thiocyanato, trihalomethanesulfonamido, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, and C-amido. each of R1-R5 is optionally substituted and independently chosen from -H, halo, alkyl, alkoxy, cycloalkoxy, haloalkyl, haloalkoxy, -L-aryl, -L-heteroaryl, -L-heterocyclyl, -L-carbocyclyl, acylamino, acyloxy, alkylthio, cycloalkylthio, alkynyl, amino, aryl, arylalkyl, arylalkenyl, arylalkynyl, arylalkoxy, aryloxy, arylthio, heteroarylthio, cyano, cyanato, haloaryl, hydroxyl, heteroaryloxy, heteroarylalkoxy, isocyanato, isothiocyanato, nitro, sulfinyl, sulfonyl, sulfonamide, thiocarbonyl, thiocyanato, trihalomethanesulfonamido, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, and C-amido; R6 is chosen from -H and alkyl; R7 is chosen from -H, alkyl, and cycloalkyl; R8 is chosen from -C(=O)NR x R y and -C(=O)R z; R x when present is chosen from -H, alkyl, alkynyl, alkenyl, -L-carbocyclyl, and -L-heterocyclyl, all of which are optionally substituted; R y when present is chosen from -H, alkyl, alkynyl, alkenyl, -L-carbocyclyl, -L-aryl, and -L-heterocyclyl, all of which are optionally substituted; R z when present is chosen from -H, alkoxy, -L-carbocyclyl, -L-heterocyclyl,and -L-aryl, wherein the aryl, heterocyclyl, or carbocyclyl is optionally substituted; each L can be saturated, partially saturated, or unsaturated, and is independently chosen from -(CH 2) n -(CH 2) n -, -(CH 2) n C(=O)(CH 2) n -, -(CH 2) n C(=O)NH(CH 2) n -, -(CH 2) n NHC(=O)O(CH 2) n -, -(CH 2) n NHC(=O)NH(CH 2) n -, -(CH 2) n NHC(=S)S(CH 2) n -,-(CH 2) n OC(=O)S(CH 2) n -, -(CH 2) n NH(CH 2) n -, -(CH 2) n O(CH 2) n -, -(CH 2) n S(CH 2) n -, and -(CH 2) n NHC(=S)NH(CH 2) n -, where each n is independently chosen from 0, 1, 2, 3, 4, 5, 6, 7, and 8; and wherein optionally substituted refers to zero or 1 to 4 optional substituents independently chosen from acylamino, acyloxy, alkenyl, alkoxy, cycloalkoxy, alkyl, alkylthio, cycloalkylthio, alkynyl, amino, aryl, arylalkyl, arylalkenyl, arylalkynyl, arylalkoxy, aryloxy, arylthio, heteroarylthio, carbocyclyl, cyano, cyanato, halo, haloalkyl, haloaryl, hydroxyl, heteroaryl, heteroaryloxy, heterocyclyl, heteroarylalkoxy, isocyanato, isothiocyanato, nitro, sulfinyl, sulfonyl, sulfonamide, thiocarbonyl, thiocyanato, trihalomethanesulfonamido, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, and C-amido.