Compounds for targeting degradation of Bruton's tyrosine kinase

A compound, wherein the compound is represented by formula (A-Ia-1):

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 is phenyl, 1,2,4-oxadiazolyl, pyrazolyl, triazolyl, or azetidinyl, each of which is optionally substituted with 1 to 3 R10;
• R10 is C1-4 alkyl, C1-4 haloalkyl or C3-6 cycloalkyl optionally substituted with 1 to 3 halogen;
• R4 is selected from H, C1-4 alkyl, halogen and —OR4a,
• R4a is C1-4 alkyl;
• Ar1 is phenyl, pyrazoyl, pyrazolo-pyridinyl, pyridinyl, pyrimidinyl, pyridazinyl, benzoisoxazolyl, benzo[cd]indol-2 (1H)-onyl, imidazo-pyridinyl or indazolyl, each or which is optionally substituted with 1 or 2 halogen;
• Z1 is a bond, CH2, NH or O;
• RD5a and RD5b are each independently H, OH, F or —OCH3;
• Y is CH, C(CH3) or —N—;
• and
• L is represented by the following formula:
• wherein:
• represents a bond to the piperidine ring;
• represents a bond to the pyrrolo[2,1-f][1,2,4]triazine ring;
• s1 is 0 or an integer from 1 to 4;
• and
• s2 is 0 or an integer from 1 to 4.