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 NR 3 ;

X 2 is C═O, and X 4 is CR 1 R 2 ;

X 3 is CR 1′ R 2′ ;

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

Y 2 and Y 3 are each CR 1 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 bound 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 1 , —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 1 , —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 are 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, or —(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;

R 1′ and R 2 ′ are 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;

R 3 and R 4 are 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 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 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 2 , wherein the compound is of the Formula IA-8:

or a pharmaceutically acceptable salt thereof.

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

or a pharmaceutically acceptable salt thereof.

5. The compound of claim 4 , wherein the compound is of the Formula IB-2:

or a pharmaceutically acceptable salt thereof.

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

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

8. The compound of claim 7 , wherein R 3 and R combine with the nitrogen atom to which they are attached to form an optionally substituted heterocycle.

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

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

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

12. The compound of claim 11 , wherein one of R 1′ and R 2′ is H and the other is optionally substituted aryl or heteroaryl.

13. The compound of claim 12 , 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.

14. The compound of claim 13 , 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.

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

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

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