A compound of general formula I: ** Formula ** in which R1a represents a hydrogen atom or a halogen atom or a hydroxy-, cyano-, C1-C6-alkyl, C1-C6-haloalkyl, C1- alkoxy group C6-, halo-C1-C6-alkoxy, C3-C6-cycloalkyloxy, (3- to 10-membered heterocycloalkyl) -O-, - NR5aR5b, -SCF3 or -SF5； R1b represents a hydrogen atom or a halogen atom or a group hydroxy-, cyano-, C1-C6-alkyl, halo C1-C6-alkyl, C1-C6-alkoxy, halo-C1-C6-alkoxy, C3-cycloalkyloxy C6-, (3-10 membered heterocycloalkyl) -O-, - NR5aR5b, -SCF3 or -SF5； R1c represents a hydrogen atom or a halogen atom or a group hydroxy-, cyano-, C1-C6-alkyl, C1-C6-haloalkyl, C1-C6-alkoxy, C3-C6-cycloalkyloxy -, (3-10 membered heterocycloalkyl) -O-, - NR5aR5b, -SCF3 or -SF5； Y represents N or CR2a； Z represents N or CR2b； with the proviso that not more than one of Y and Z represents N； R2a represents a hydrogen atom or a halogen atom or a group selected from: C1-C6-alkyl, C2-C6-alkenyl, C3-C6-alkynyl, C3-C6-cycloalkyl, 3- to 10-membered heterocycloalkyl-, heterocycloalkenyl - from 4 to 10 members, aryl-, heteroaryl-, halo-C1-C3-alkyl-, cyano-, - (CH2) qX- (CH2) p-R3； wherein said C1-C6-alkyl, C3-C6-cycloalkyl-, 3-10 membered heterocycloalkyl-, 4-10 membered heterocycloalkenyl-, aryl- or heteroaryl- are optionally substituted, identically or differently, with 1 , 2, 3, 4 or 5 R4 groups； R2b represents a hydrogen atom or a halogen atom or a group selected from: C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, C3-C6-cycloalkyl, 3- to 10-membered heterocycloalkyl-, heterocycloalkenyl - from 4 to 10 members, aryl-, heteroaryl-, halo-C1-C3-alkyl-, cyano-, - (CH2) qX- (CH2) p-R3； wherein said C1-C6-alkyl, C3-C6-cycloalkyl-, 3-10 membered heterocycloalkyl-, 4-10 membered heterocycloalkenyl-, aryl- or heteroaryl- are optionally substituted, identically or differently, with 1 , 2, 3, 4 or 5 R4 groups； X represents a single bond or a bivalent group selected from: -O-, -S-, -S (>； = O) -, -S (>； = O) 2-, -S (>； = O) - (NR3a) -, - (NR3a)
