Bifunctional compounds for degrading BTK via ubiquitin proteosome pathway

A compound of Formula (I)

• or a pharmaceutically acceptable salt thereof, wherein
• R1 is —H or —C1-4 alkyl;
• XA is N;
• XB is N;
• XC is CR2;
• R2 is —H, or
• R1 and R2 taken together with the atoms to which they are attached form a monocyclic heterocycle fused to ring E;
• ring A is phenyl, a 4-6 membered monocyclic heteroaryl group having 1-3 heteroatoms independently selected from N, O, and S, or a 9-10 membered bicyclic heteroaryl having 1-3 heteroatoms independently selected from N, O, and S, wherein ring A is optionally substituted with —ZA—RA;
• ZA is a bond, or an optionally substituted branched or straight C1-3 aliphatic chain wherein up to two carbon units of ZA are optionally and independently replaced by —C(O)—, —C(S)—, —N(R)—, —C(O)N(R)—, —N(R)C(O)—, —CO2—, —OCO—, —O—, —S—, —S(O)—, —S(O)2, —S(O)2N(R)—, or —N(R)S(O)2—;
• RA is hydrogen, halo, —OH, —NH2, —NO2, —CN, —CF3, —CH3, or —OCH3;
• ring B is
• L is —X1—X2—X3—X4—;
• X1 is —N(R)—C(O)—O—, —N(R)—C(O)—, —C(O)—N(R)—, or 7-12 membered spiro bicyclic heterocycloalkyl ring system having 1-3 heteroatoms independently selected from N, O, or S, wherein the spiro bicyclic heterocycloalkyl ring system is optionally substituted with —OH or oxo;
• X2 is a bond, —(CH2)n—O—, —O—(CH2)n—, —C1-8 alkyl-, a 7-12 membered spiro bicyclic heterocycloalkyl ring system having 1-3 heteroatoms independently selected from N, O, or S, a 4-6 membered monocyclic heterocycloalkyl having 1-2 heteroatoms independently selected from N, O, or S, a 6-10 membered fused bicyclic heterocycloalkyl having 1-3 heteroatoms independently selected from N, O, or S, or a 6-9 membered bridged bicyclic heterocycloalkyl having 1-3 heteroatoms independently selected from N, O, or S, wherein the spiro bicyclic heterocycloalkyl ring system is optionally substituted with —OH or oxo;
• X3 is a bond, —O—, —(CH2)n—O—, —C1-4 alkyl-, or a 4-6 membered heterocycloalkyl ring having 1-2 heteroatoms independently selected from N, O, or S;
• X4 is a bond, —C1-4 alkyl-, or a 4-6 membered heterocycloalkyl ring having 1-2 heteroatoms independently selected from N, O, or S;
• each R is independently —H or —C1-3 alkyl;
• Y is
• wherein:
• each R4 is independently halo or C1-4 alkyl;
• each ZB is —C(RB)2— or —C(O)—;
• each RB is —H or —C1-4 alkyl;
• each n is independently 1, 2, or 3;
• and
• q is 0, 1, or 2.