3-aryl-4-amido-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 and X4 are each CR1R2;
• X3 is CR1′R2′;
• Y1 and Y4 are not bonded to —C(O)NHOH and are each independently N or CR1;
• Y2 and Y3 are each independently N or CR1 when not bonded to —C(O)NHOH, and Y2 and Y3 are C when bonded to —C(O)NHOH;
• wherein one of Y1, Y2, Y3, and Y4 is N;
• L is selected from the group consisting of —C(O)—, —C(O)(CR1R2)m, and —C(O)(CR1R2)mO—, wherein L is bound to the ring nitrogen through the carbonyl group;
• R 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, —O5—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, with the proviso that R is not bound to L via a nitrogen atom;
• each R1 and R2 are independently, 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)2C1-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, and —(CHR5)nNR3R4, 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, —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 R1′ and R2′ are independently 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;
• R3 and R4 are independently, 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)2C1-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), —NHC1-C6 alkyl, —N(C1-C6 alkyl)2, —S(O)2N(C1-C6 alkyl)2, —S(O)2NH(C1-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;
• R5 is independently, 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;
• each n is independently and at each occurrence an integer from 0 to 6;
• and
• each m is independently and at each occurrence an integer from 1 to 6.