Azaindoles useful as inhibitors of jak and other protein kinases

A method of inhibiting JAK-3, ROCK, or Aurora kinase activity in a biological sample comprising the step of contacting said biological sample with a compound of formula (I):

• or pharmaceutically acceptable salts thereof, wherein:
• R1 is T-R′ or is —Si(R′)3;
• R2, R3, and R4 are each independently halogen, —CN, —NO2, or V—R′;
• X1, X2 and X3 are each independently N, or CH, wherein the hydrogen atom of CH is optionally replaced by R5;
• x is 1, 2, 3, or 4;
• each occurrence of R5 is independently halogen, CN, NO2, or U—R′, wherein at least one R5 is other than H;
• T, V, and U are each independently a bond or an optionally substituted C1-C6 alkylidene chain, wherein up to two methylene units of the chain are optionally and independently replaced by —NR′—, —S—, —O—, —CS—, —CO2—, —OCO—, —CO—, —COCO—, —CONR′—, —NR′CO—, —NR′CO2—, —SO2NR′—, —NR′SO2—, —CONR′NR′—, —NR′CONR′—, —OCONR′—, —NR′NR′—, —NR′SO2NR′—, —SO—, —SO2—, —PO—, —PO2—, or —POR′—;
• and
• each occurrence of R′ is independently hydrogen or an optionally substituted group selected from a C1-C6 aliphatic group, a 3-8-membered saturated, partially unsaturated, or fully unsaturated monocyclic ring having 0-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-12 membered saturated, partially unsaturated, or fully unsaturated bicyclic ring system having 0-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• or two occurrences of R′, are taken together with the atom(s) to which they are bound to form an optionally substituted 3-12 membered saturated, partially unsaturated, or fully unsaturated monocyclic or bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, provided that:
• a) if R1 is substituted cyclopentyl, x is 1, X1 and X3 are CH, then X2 is not C—R5, where R5 is fluoro or OMe;
• b) if R2 and R3 are simultaneously H and R1 and R4 are independently selected from H or Me, x is 1, X1 and X3 are CH, then X2 is not C—R5, where R5 is OMe, NO2, or fluoro;
• c) if R1, R2, R3 and R4 are simultaneously H, x is 1, R5 is —SMe, —NH2 or an optionally substituted NH-piperidine, and X1 and X2 are N, then X3 is not CH;
• d) if R2, R3 and R4 are simultaneously H, X1, X2 and X3 are CH, and two R5 form a fused optionally substituted bicyclic ring with the ring to which they are attached, then R1 is not CH2CH2N(Me)2;
• e) if R2 and R3 are simultaneously H, R4 is NH2, and X1, X2 and X3 are CH, then R1 is not substituted phenyl;
• f) if R2, R3 and R4 are simultaneously H, then R1 is not Si(R′)3;
• and
• g) if R1, R2 and R4 are simultaneously H and (i) X2 and X3 are CH or CR5 or (ii) any one of X1, X2 or X3 are N, then R3 is not phenyl or phenyl substituted with O-phenyl or N(Me)2.