A compound of the formula: wherein R 5 is selected from haloalkyl, alkoxy, cyano, halogen, acyl, aminoacyl, and nitro; Y 1 and Y 2 are independently selected from hydrogen, alkyl, and acyl; R 1 is selected from hydrogen and alkyl; R a and R b are independently selected from hydrogen and alkyl; R c and R d are independently selected from hydrogen and alkyl; R 6a is selected from hydrogen, alkyl, cyano, halogen, acyl, aminoacyl, nitro, and cycloalkyl; R 6b is fluoro; R 7b is selected from hydrogen, alkyl, cyano, halogen, acyl, aminoacyl, nitro, and cycloalkyl; R 8 is selected from cyclopropyl and substituted cyclopropyl, wherein the substituent is haloalkyl; R 7x is selected from hydrogen, alkyl, haloalkyl, and cycloalkyl; or a salt or stereoisomer thereof; wherein: "alkyl" is a monovalent saturated aliphatic hydrocarbyl group having from 1 to 10 carbon atoms; "haloalkyl" is a substituted alkyl group, wherein one or more hydrogen atoms on the alkyl group have been substituted with a halo group; "alkoxy" is a group -O-alkyl; "alkenyl" is a straight chain or branched hydrocarbyl group having from 2 to 6 carbon atoms and having at least 1 site of double bond unsaturation; "alkynyl" is a straight or branched monovalent hydrocarbyl group having from 2 to 6 carbon atoms and having at least 1 site of triple bond unsaturation; "cycloalkyl" is a cyclic alkyl group of from 3 to 10 carbon atoms having single or multiple cyclic rings; "cycloalkenyl" is a non-aromatic cyclic alkyl group of from 3 to 10 carbon atoms having single or multiple rings and having at least one double bond; "aryl" is a monovalent aromatic carbocyclic group of from 6 to 14 carbon atoms having a single ring or multiple condensed rings, which condensed rings may or may not be aromatic, provided that the point of attachment is through an atom of the aromatic aryl group; "heteroaryl" is an aromatic group of from 1 to 10 carbon atoms and 1 to 4 heteroatoms selected from oxygen, nitrogen, and sulfur within the ring; "heterocyclyl" is a saturated or unsaturated group having a single ring or multiple condensed rings and having from 3 to 15 ring atoms, including 1 to 4 hetero atoms; and "acyl" is a group H-C -, alkyl-C -, alkenyl-C -, alkynyl-C -, cycloalkyl-C -, cycloalkenyl-C -, aryl-C -, heteroaryl-C -, or heterocyclyl-C -. R 5 is selected from haloalkyl, alkoxy, cyano, halogen, acyl, aminoacyl, and nitro; Y 1 and Y 2 are independently selected from hydrogen, alkyl, and acyl; R 1 is selected from hydrogen and alkyl; R a and R b are independently selected from hydrogen and alkyl; R c and R d are independently selected from hydrogen and alkyl; R 6a is selected from hydrogen, alkyl, cyano, halogen, acyl, aminoacyl, nitro, and cycloalkyl; R 6b is fluoro; R 7b is selected from hydrogen, alkyl, cyano, halogen, acyl, aminoacyl, nitro, and cycloalkyl; R 8 is selected from cyclopropyl and substituted cyclopropyl, wherein the substituent is haloalkyl; R 7x is selected from hydrogen, alkyl, haloalkyl, and cycloalkyl; "alkyl" is a monovalent saturated aliphatic hydrocarbyl group having from 1 to 10 carbon atoms; "haloalkyl" is a substituted alkyl group, wherein one or more hydrogen atoms on the alkyl group have been substituted with a halo group; "alkoxy" is a group -O-alkyl; "alkenyl" is a straight chain or branched hydrocarbyl group having from 2 to 6 carbon atoms and having at least 1 site of double bond unsaturation; "alkynyl" is a straight or branched monovalent hydrocarbyl group having from 2 to 6 carbon atoms and having at least 1 site of triple bond unsaturation; "cycloalkyl" is a cyclic alkyl group of from 3 to 10 carbon atoms having single or multiple cyclic rings; "cycloalkenyl" is a non-aromatic cyclic alkyl group of from 3 to 10 carbon atoms having single or multiple rings and having at least one double bond; "aryl" is a monovalent aromatic carbocyclic group of from 6 to 14 carbon atoms having a single ring or multiple condensed rings, which condensed rings may or may not be aromatic, provided that the point of attachment is through an atom of the aromatic aryl group; "heteroaryl" is an aromatic group of from 1 to 10 carbon atoms and 1 to 4 heteroatoms selected from oxygen, nitrogen, and sulfur within the ring; "heterocyclyl" is a saturated or unsaturated group having a single ring or multiple condensed rings and having from 3 to 15 ring atoms, including 1 to 4 hetero atoms; and "acyl" is a group H-C -, alkyl-C -, alkenyl-C -, alkynyl-C -, cycloalkyl-C -, cycloalkenyl-C -, aryl-C -, heteroaryl-C -, or heterocyclyl-C -.