Furo[3,4-b]pyrrole-containing btk inhibitor

A compound of formula (I), a stereoisomer thereof or a pharmaceutically acceptable salt thereof,

• wherein,
• ring B is selected from the group consisting of 5-10 membered heteroaryl and C6-10 aryl;
• R1 is independently selected from the group consisting of halogen, —OH, —NH2, cyano, C1-6 alkyl and C1-6 alkoxy, wherein C1-6 alkyl or C1-6 alkoxy is optionally substituted with halogen;
• m is 0, 1, 2, 3 or 4;
• L is selected from the group consisting of —C(O)NH—, —NHC(O)—, —O—, —NH—, —S—, —C(O)O—, —OC(O)—, —S(O)2O— and —OS(O)2—;
• R2 is independently selected from the group consisting of halogen, —OH, —NH2, cyano, C1-6 alkyl and C1-6 alkoxy, wherein C1-6 alkyl or C1-6 alkoxy is optionally substituted with halogen;
• n is 0, 1, 2, 3 or 4;
• R3 is selected from the group consisting of H, RaC(O)—, RaS(O)2— and Ra—;
• R5 is independently selected from the group consisting of halogen, —OH, —NH2, cyano, C1-6 alkyl and C1-6 alkoxy;
• p is 0, 1, 2 or 3;
• R4 is selected from the group consisting of hydrogen, RaS(O)2—, (RaO)2P(O)— and RaC(O)—;
• wherein Ra is independently selected from the group consisting of C2-6 alkynyl, C2-6 alkenyl, C1-6 alkyl, C3-6 cycloalkyl, (C1-6 alkyl)NH—, (C1-6 alkyl)2N—, 3- to 6-membered heterocycloalkyl, 5- to 10-membered heteroaryl and C6-10 aryl, wherein Ra is optionally substituted with (C1-6 alkyl)2N—, (C1-6 alkyl)NH—, hydroxy, amino, halogen or cyano.