Substituted 1,2,3,8,9,9a-hexahydro-5H-pyrrolo[1,2-a]azepin-5-ones as factor XIa inhibitors

A compound of formula (I):

• or a pharmaceutically acceptable salt or stereoisomer thereof,
• wherein:
• Q is C(O)NHR6 or
• R′ is halogen, CN, NO2, C1-4 alkyl, C1-4 fluoroalkyl, C(O)C1-4 alkyl, NRARB, OH, OC1-4 alkyl, OC1-4 fluoroalkyl, C3-6 cycloalkyl, phenyl, or 5- or 6-membered heterocyclyl, wherein the C3-6 cycloalkyl, phenyl, or 5- or 6-membered heterocyclyl is optionally substituted with one or more substituents independently selected from the group consisting of halogen, CN, C1-4 alkyl, C1-4 fluoroalkyl, C1-4 alkylene-NRARB, C(O)OH, C(O)OC1-4 alkyl, NRARB, OH, OC1-4 alkyl, OC1-4 fluoroalkyl, C3-7 cycloalkyl, and 5- or 6-membered heterocyclyl;
• each R2 is independently F, Cl, CH3, or OCH3;
• R4 is H or halogen;
• R5 is phenyl or 5- or 6-membered heteroaryl, wherein the phenyl or 5- or 6-membered heteroaryl is optionally substituted with one or two substituents independently selected from the group consisting of halogen, C1-4 alkyl, C1-2, fluoroalkyl, C1-2, hydroxyalkyl, C(O)NRCRD, C(O)OH, C(O)OC1-4 alkyl, NRARB, and NRCC(O)C1-2 alkyl;
• R6 is phenyl or 9- or 10-membered heteroaryl, wherein the phenyl or 9- or 10-membered heteroaryl is optionally substituted with one or two substituents independently selected from the group consisting of halogen, C1-4 alkyl, C1-2, fluoroalkyl, C1-2, hydroxyalkyl, C(O)NRERF, C(O)OH, C(O)OC1-4 alkyl, Nine, and NRCC(O)C1-2 alkyl;
• each RA is independently H or C1-4 alkyl;
• each RB is independently H or C1-4 alkyl;
• each RC is independently H, C1-2 alkyl, or C1-4 hydroxyalkyl;
• each RD is independently H, C1-2 alkyl, or C1-4 hydroxyalkyl;
• each RE is independently H or C1-4 alkyl;
• each RF is independently H or C1-4 alkyl;
• and
• a is 0, 1, 2, or 3.