3-aryl-bicyclic [4,5,0] hydroxamic acids as HDAC inhibitors

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof,

wherein:

X 1 is CR 1 R 2 or C═O;

X 2 and X 4 are each independently CR 1 R 2 , C═O, S(O) or SO 2 ;

X 3 is CR 1′ R 2′ ; wherein X 4 , X 2 , and X 1 are not all simultaneously CR 1 R 2 ;

Y 1 and Y 4 are not bonded to —C(O)NHOH and are each independently N or CR 1 ;

Y 2 and Y 3 are each independently N or CR′ when not bonded to C(O)NHOH and Y 2 and Y 3 are C when bonded to —C(O)NHOH;

L is selected from the group consisting of a bond, —(CR 1 R 2 ) n —, —C(O)O—, —C(O)NR 3 —, —S(O) 2 —, —S(O) 2 NR 3 —, —S(O)—, and —S(O)NR 3 —, wherein L is bonded to the ring nitrogen through the carbonyl or sulfonyl group;

R is independently selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 4 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, —C 5 -C 12 spirocyclyl, heterocyclyl, spiroheterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, spirocyclyl, heterocyclyl, spiroheterocyclyl, aryl, or heteroaryl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, oxo, —NO 2 , —CN, —R 2 , —OR 3 , —NHR 3 , —NR 3 R 4 , —S(O) 2 NR 3 R 4 , —S(O) 2 R 1 , —C(O)R 1 , —CO 2 R 1 , —NR 3 S(O) 2 R 1 , —S(O)R′, —S(O)NR 3 R 4 , —NR 3 S(O)R 1 , heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O;

each R 1 and R 2 is independently, and at each occurrence, selected from the group consisting of —H, —R 3 , —R 4 , —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 4 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, —OH, halogen, —NO 2 , —CN, —NHC 1 -C 6 alkyl, —N(C 1 -C 6 alkyl) 2 , —S(O) 2 N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O) 2 R 5 , —S(O) 2 (C 1 -C 6 alkyl), —(C 1 -C 6 alkyl)S(O) 2 R 5 , —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)S(O) 2 C 1 -C 6 alkyl, and —(CHR 5 ) n NR 3 R 4 , wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl is optionally substituted with one or more substituents selected from —OH, halogen, —NO 2 , oxo, —CN, —R 5 , —OR 3 , —NHR 3 , NR 3 R 4 , —S(O) 2 N(R 3 ) 2 —, —S(O) 2 R 5 , —C(O)R 5 , —CO 2 R 5 , —NR 3 S(O) 2 R 5 , —S(O)R 5 , —S(O)NR 3 R 4 , —NR 3 S(O)R 5 , heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O;

or R 1 and R 2 can combine with the atom to which they are both attached to form a spirocycle, spiroheterocycle, or a spirocycloalkenyl;

or R 1 and R 2 , when on adjacent atoms, can combine to form a heterocycle, cycloalkyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, or cycloalkenyl;

or R 1 and R 2 , when on non-adjacent atoms, can combine to form a bridging cycloalkyl, cycloalkenyl, or heterocycloalkyl;

each R 1′ and R 2′ is independently, and at each occurrence, selected from the group consisting of H, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, wherein each aryl or heteroaryl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, —NO 2 , oxo, —CN, —R 3 , —R 5 , —OR 3 , —NHR 3 , —NR 3 R 4 , —S(O) 2 N(R 3 ) 2 , —S(O) 2 R 5 , —C(O)R 5 , —CO 2 R 5 , —NR 3 S(O) 2 R 5 , —S(O)R 5 , —S(O)NR 3 R 4 , —NR 3 S(O)R 5 , heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, wherein at least one of R 1′ or R 2′ is not H;

each R 3 and R 4 is independently, and at each occurrence, selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 4 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, —S(O) 2 N(C 1 -C 6 alkyl) 2 , —S(O) 2 (C 1 -C 6 alkyl), —(C 1 -C 6 alkyl)S(O) 2 R 5 , —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, and —(CHR 5 ) n N(C 1 -C 6 alkyl) 2 , wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, —NO 2 , oxo, —CN, —R 5 , —O(C 1 -C 6 ) alkyl, —NH(C 1 -C 6 ) alkyl, —N(C 1 -C 6 alkyl) 2 , —S(O) 2 N(C 1 -C 6 alkyl) 2 , —S(O) 2 NHC 1 -C 6 alkyl, —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)S(O) 2 C 1 -C 6 alkyl, —S(O)R 5 , —S(O)N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O)R 5 , heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O;

or R 3 and R can combine with the nitrogen atom to which they are attached to form a heterocycle or heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, wherein each heterocycle or heteroaryl is optionally substituted with —R 4 , —OR 4 , or —NR 4 R 5 ;

R 5 is independently, and at each occurrence, selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 4 -C 5 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 5 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, —OH, halogen, —NO 2 , —CN, —NHC 1 -C 6 alkyl, —N(C 1 -C 6 alkyl) 2 , —S(O) 2 NH(C 1 -C 6 alkyl), —S(O) 2 N(C 1 -C 6 alkyl) 2 , —S(O) 2 C 1 -C 6 alkyl, —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)SO 2 C 1 -C 6 alkyl, —S(O)(C 1 -C 6 alkyl), —S(O)N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O)(C 1 -C 6 alkyl) and —(CH 2 ) n N(C 1 -C 6 alkyl) 2 ; and

each n is independently and at each occurrence an integer from 0 to 6.

2. The compound of claim 1 , wherein the compound is of the Formula IA:

or a pharmaceutically acceptable salt thereof.

3. The compound of claim 1 , wherein the compound is of the Formula IB:

or a pharmaceutically acceptable salt thereof.

4. The compound of claim 1 , wherein L is —C(O)NR 3 —.

5. The compound of claim 1 , wherein one of R 1′ and R 2′ is H and the other of R 1′ and R 2′ is optionally substituted aryl or optionally substituted heteroaryl.

6. The compound of claim 5 , wherein the R 3 and R combine with the nitrogen atom to which they are attached to form an optionally substituted heterocycle.

7. The compound of claim 6 , wherein one of R 1′ and R 2′ is H and the other of R 1′ and R 2′ is optionally substituted aryl.

8. The compound of claim 6 , wherein one of R 1′ and R 2′ is H and the other of R 1′ and R 2′ is optionally substituted heteroaryl.

9. The compound of claim 1 , wherein L is a bond.

10. The compound of claim 9 , wherein one of R 1′ and R 2′ is H and the other of R 1′ and R 2′ is optionally substituted aryl or optionally substituted heteroaryl.

11. The compound of claim 10 , wherein R is an optionally substituted group selected from the group consisting of —C 1 -C 6 alkyl, —C 3 -C 8 cycloalkyl, heterocyclyl, aryl, or heteroaryl.

12. The compound of claim 11 , wherein R is —C 1 -C 6 alkyl substituted with an optionally substituted group selected from the group consisting of aryl, heteroaryl, or —C 3 -C 8 cycloalkyl.

13. The compound of claim 12 , wherein one of R 1′ and R 2′ is H and the other of R 1′ and R 2′ is optionally substituted aryl.

14. The compound of claim 12 , wherein one of R 1′ and R 2′ is H and the other of R 1′ and R 2′ is optionally substituted heteroaryl.

15. A pharmaceutical composition comprising a compound of claim 1 , and a pharmaceutically acceptable carrier.