HETEROCYCLIC COMPOUNDS USEFUL AS PDK1 INHIBITORS

1 . A compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein:

R 1 is hydrogen or optionally substituted C 1-6 aliphatic, or:

R 1 and a substituent on Ring A 4 are taken together with their intervening atoms to form an optionally substituted 5-7 membered partially unsaturated or aromatic fused ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

X is —C(O)— or —S(O) 2 —,

L 1 is a covalent bond or C 1-4 alkylene optionally substituted with —(CH 2 ) 0-4 R ◯ or —(CH 2 ) 0-4 OR ◯ , wherein R ◯ is hydrogen;

A 1 is a covalent bond or an optionally substituted bivalent ring selected from 3-7 membered saturated or partially unsaturated monocyclic carbocyclylene, 7-10 membered saturated or partially unsaturated bicyclic carbocyclylene, 4-7 membered saturated or partially unsaturated monocyclic heterocyclylene having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 7-10 membered saturated or partially unsaturated bicyclic heterocyclylene having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, phenylene, 8-10 membered bicyclic arylene, 5-6 membered monocyclic heteroarylene having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or 8-10 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

L 2 is a covalent bond or an optionally substituted alkylene chain;

Ring A 2 is a 3-7 membered saturated or partially unsaturated monocyclic carbocyclic ring, a 7-10 membered saturated or partially unsaturated bicyclic carbocyclic ring, a 4-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 7-10 membered saturated or partially unsaturated bicyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a phenyl ring, an 8-10 membered bicyclic aryl ring, a 5-6 membered monocyclic heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, an 8-10 membered bicyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 10-16 membered saturated, partially unsaturated, or aromatic tricyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, wherein Ring A 2 is optionally substituted with 1-4 R x groups;

each R x is independently —R, optionally substituted alkylidenyl, oxo, -halo, —NO 2 , —CN, —OR, —SR, —N(R′) 2 , —C(O)R, —CO 2 R, —C(O)C(O)R, —C(O)CH 2 C(O)R, —S(O)R, —S(O) 2 R, —C(O)N(R′) 2 , —S(O) 2 N(R′) 2 , —OC(O)R, —N(R′)C(O)R, —N(R′)N(R′) 2 , —N(R′)OR, —N(R′)C(═NR′)N(R′) 2 , —C(═NR′)N(R′) 2 , —C═NOR, —N(R′)C(O)N(R′) 2 , —N(R′)S(O) 2 N(R′) 2 , —N(R′)S(O) 2 R, or —OC(O)N(R′) 2 ;

each R is independently hydrogen or an optionally substituted group selected from C 1-6 aliphatic, a 3-7 membered saturated or partially unsaturated monocyclic carbocyclic ring, a 7-10 membered saturated or partially unsaturated bicyclic carbocyclic ring, a 4-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 7-10 membered saturated or partially unsaturated bicyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a phenyl ring, an 8-10 membered bicyclic aryl ring, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

each R′ is independently —R, or two R′ groups on the same nitrogen are taken together with their intervening atoms to form an optionally substituted 5-8 membered saturated, partially unsaturated, or aromatic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

L 3 is unsubstituted methylene or methylene substituted with methyl or ethyl;

Ring A 3 is an optionally substituted ring selected from a 3-7 membered saturated or partially unsaturated monocyclic carbocyclic ring, a 7-10 membered saturated or partially unsaturated bicyclic carbocyclic ring, a 4-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 7-10 membered saturated or partially unsaturated bicyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a phenyl ring, an 8-10 membered bicyclic aryl ring, a 5-6 membered monocyclic heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

Ring A 4 is pyridinyl, wherein any substitutable carbon on Ring A 4 is optionally substituted with R 3 , R 4 , or R 5 ;

each of R 3 , R 4 , and R 5 is independently —R, -halo, —NO 2 , —CN, —OR, —SR, —N(R′) 2 , —C(O)R, —CO 2 R, —C(O)C(O)R, —C(O)CH 2 C(O)R, —S(O)R, —S(O) 2 R, —C(O)N(R′) 2 , —S(O)N(R′) 2 , —S(O) 2 N(R′) 2 , —OC(O)R, —N(R′)C(O)R, —N(R′)N(R′) 2 , —N(R′)OR, —N(R′)C(═NR′)N(R′) 2 , —C(═NR′)N(R′) 2 , —C═NOR, —N(R′)C(O)N(R′) 2 , —N(R′)S(O) 2 N(R′) 2 , —N(R′)S(O) 2 R, or —OC(O)N(R′) 2 , or

R 3 and R 4 or R 4 and R 5 are taken together with their intervening atoms to form an optionally substituted fused ring selected from a 4-7 membered partially unsaturated carbocyclic ring, phenyl, a 5-6 membered partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

2 .- 9 . (canceled)

10 . The compound of claim 1 , wherein:

R 3 is hydrogen, —Cl, or —CF 3 ;

R 4 is halo, —NH 2 , —CN, —NO 2 , —SC 1-4 alkyl, —S(O)C 1-4 alkyl, —S(O) 2 C 1-4 alkyl, —S(O)N(R′) 2 , —CF 3 , —OCH 3 , —OCH 2 CH 3 , benzyloxy, —C(O)N(R′) 2 , or —NHC(O)C 1-4 alkyl and

each R′ is independently hydrogen or C 1-4 alkyl, or two R′ groups on the same nitrogen are takes together with the intervening nitrogen to form an optionally substituted 5-6 membered saturated, partially unsaturated, or aromatic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

11 .- 15 . (canceled)

16 . The compound of claim 1 , wherein Ring A 3 is phenyl, an 8-10 membered bicyclic aryl ring, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaryl ring having 1-4 heteroatoms selected from nitrogen, oxygen, or sulfur, wherein Ring A 3 is optionally substituted with one or more halo or alkyl groups.

17 . (canceled)

18 . The compound of claim 1 , wherein L 1 is optionally substituted C 1-3 alkylene.

19 .- 22 . (canceled)

23 . The compound of claim 1 , wherein A 1 is a covalent bond or a optionally substituted bivalent ring selected from phenylene, an 8-10 membered bicyclic arylene, a 5-6 membered heteroarylene having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

24 . (canceled)

25 . The compound of claim 1 , wherein L 2 is a covalent bond or an optionally substituted methylene.

26 . The compound of claim 1 , wherein Ring A 2 is optionally substituted with 1-4 R x groups and is selected from phenyl, an 8-10 membered bicyclic aryl ring, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

27 .- 31 . (canceled)

32 . The compound of claim 1 , wherein the compound is of formula II:

or a pharmaceutically acceptable salt thereof.

33 - 45 . (canceled)

46 . A compound selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

47 . A pharmaceutical composition containing a compound of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

48 . A pharmaceutical composition containing a compound of claim 46 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

49 . A method of treating cancer in a subject in need thereof, said method comprising administering to said subject a therapeutically effective amount of a compound of claim 1 , or a pharmaceutically acceptable salt thereof, or a composition of claim 47 .

50 . A method of treating cancer in a subject in need thereof, said method comprising administering to said subject a therapeutically effective amount of a compound of claim 46 , or a pharmaceutically acceptable salt thereof, or a composition of claim 48 .