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

A compound of Formula I:

• or a pharmaceutically acceptable salt thereof,
• wherein:
• X1 is O;
• X2 is CR1R2, and X4 is C═O;
• X3 is CR1′R2′;
• Y1 and Y4 are not bonded to —C(O)NHOH and are each CR1;
• one of Y2 and Y3 is CR1, and the other of Y2 and Y3 is C—C(O)NHOH;
• L is selected from the group consisting of a bond, —(CR1R2)n—, —C(O)O—, —C(O)NR3—, —S(O)2—, —S(O)2NR3—, —S(O)—, and —S(O)NR3—, wherein L is bound to the ring nitrogen through the carbonyl or sulfonyl group;
• R is independently selected from the group consisting of —H, —C1-C6 alkyl, —C2-C6 alkenyl, —C4-C8 cycloalkenyl, —C2-C6 alkynyl, —C3-C8 cycloalkyl, —C5-C12 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, —NO2, —CN, —R1, —R2, —OR3, —NHR3, —NR3R4, —S(O)2NR3R4, —S(O)2R1, —C(O)R1, —CO2R1, —NR3S(O)2R1, —S(O)R1, —S(O)NR3R4, —NR3S(O)R1, heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O;
• each R1 and R2 is independently, and at each occurrence, selected from the group consisting of —H, —R3, —R4, —C1-C6 alkyl, —C2-C6 alkenyl, —C4-C8 cycloalkenyl, —C2-C6 alkynyl, —C3-C8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, —OH, halogen, —NO2, —CN, —NHC1-C6 alkyl, —N(C1-C6 alkyl)2, —S(O)2N(C1-C6 alkyl)2, —N(C1-C6 alkyl)S(O)2R5, —S(O)2(C1-C6 alkyl), —(C1-C6 alkyl)S(O)2R5, —C(O)C1-C6 alkyl, —CO2C1-C6 alkyl, —N(C1-C6 alkyl)S(O)2C1-C6 alkyl, or —(CHR5)nNR3R4, wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl is optionally substituted with one or more substituents selected from —OH, halogen, —NO2, oxo, —CN, —R5, —OR3, —NHR3, —NR3R4, —S(O)2N(R3)2, —S(O)2R5, —C(O)R5, —CO2R5, —NR3S(O)2R5, —S(O)R5, —S(O)NR3R4, —NR3S(O)R5, heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O;
• each of R1′ and R2′ 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, —NO2, oxo, —CN, —R3, —R5, —OR3, —NHR3, —NR3R4, —S(O)2N(R3)2, —S(O)2R5, —C(O)R5, —CO2R5, —NR3S(O)2R5, —S(O)R5, —S(O)NR3R4, —NR3S(O)R5, 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 R1′ or R2′ is not H;
• each R3 and R4 is independently, and at each occurrence, selected from the group consisting of —H, —C1-C6 alkyl, —C2-C6 alkenyl, —C4-C8 cycloalkenyl, —C2-C6 alkynyl, —C3-C8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, —S(O)2N(C1-C6 alkyl)2, —S(O)2(C1-C6 alkyl), —(C1-C6 alkyl)S(O)2R5, —C(O)C1-C6 alkyl, —CO2C1-C6 alkyl, and —(CHR5)nN(C1-C6 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, —NO2, oxo, —CN, —R5, —O(C1-C6) alkyl, —NH(C1-C6) alkyl, —N(C1-C6 alkyl)2, —S(O)2N(C1-C6 alkyl)2, —S(O)2NHC1-C6 alkyl, —C(O)C1-C6 alkyl, —CO2C1-C6 alkyl, —N(C1-C6 alkyl)S(O)2C1-C6 alkyl, —S(O)R5, —S(O)N(C1-C6 alkyl)2, —N(C1-C6 alkyl)S(O)R5, heterocyclyl, aryl, and heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O;
• or R3 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 —R4, —OR4, or —NR4R5;
• R5 is independently, and at each occurrence, selected from the group consisting of —H, —C1-C6 alkyl, —C2-C6 alkenyl, —C4-C8 cycloalkenyl, —C2-C6 alkynyl, —C3-C8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1 to 5 heteroatoms selected from the group consisting of N, S, P, and O, —OH, halogen, —NO2, —CN, —NHC1-C6 alkyl, —N(C1-C6 alkyl)2, —S(O)2NH(C1-C6 alkyl), —S(O)2N(C1-C6 alkyl)2, —S(O)2C1-C6 alkyl, —C(O)C1-C6 alkyl, —CO2C1-C6 alkyl, —N(C1-C6 alkyl)SO2C1-C6 alkyl, —S(O)(C1-C6 alkyl), —S(O)N(C1-C6 alkyl)2, —N(C1-C6 alkyl)S(O)(C1-C6 alkyl) and —(CH2)nN(C1-C6 alkyl)2;
• and
• each n is independently and at each occurrence an integer from 0 to 6.