Antiproliferative compounds and methods of use thereof

1. A pharmaceutical composition comprising a compound of Formula I:

or an enantiomer or a mixture of enantiomers thereof, or a pharmaceutically acceptable salt, solvate, or hydrate, thereof, wherein:

R 1 is optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl or optionally substituted heterocyclyl;

R 2 and R 3 are each halo;

where the substituents on R 1 , when present, are one to three groups Q, where each Q is independently alkyl, halo, haloalkyl, alkoxyalkyl, oxo, hydroxyl, alkoxy, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted aryl, optionally substituted heteroaryl, —R 4 OR 5 , —R 4 OR 5 —R 4 OR 5 , —R 4 N(R 6 )(R 7 ), —R 4 SR 5 , —R 4 OR 4 N(R 6 )(R 7 ), —R 4 OR 4 C(J)N(R 6 )(R 7 ), —C(J)R 9 or R 4 S(O) t R 8 ;

each R 4 is independently alkylene, alkenylene or a direct bond;

each R 5 is independently hydrogen, alkyl, haloalkyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl or heterocyclylalkyl, where alkyl, haloalkyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl or heterocyclylalkyl groups in R 5 are each independently optionally substituted with 1-3 Q 1 groups, where each Q 1 is independently alkyl, haloalkyl or halo;

R 6 and R 7 are selected as follows:

i) R 6 and R 7 are each independently hydrogen or alkyl; or

ii) R 6 and R 7 together with the nitrogen atom on which they are substituted form a 5 or 6-membered heterocyclyl or heteroaryl ring, optionally substituted with one or two halo, alkyl or haloalkyl;

R 8 is alkyl, haloalkyl, or hydroxyalkyl;

R 9 is alkyl or aryl;

J is O or S; and

t is 1 or 2.

2. The pharmaceutical composition of claim 1 , wherein the compound has formula III

or an enantiomer or a mixture of enantiomers thereof, or a pharmaceutically acceptable salt, solvate, or hydrate, thereof, wherein:

each Q 1 is independently alkyl, halo, haloalkyl, alkoxyalkyl, hydroxyl, alkoxy, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted aryl, —R 4 OR 5 , —R 4 SR 5 , —R 4 N(R 6 )(R 7 ), R 4 OR 4 N(R 6 )(R 7 ) or R 4 OR 4 C(J)N(R 6 )(R 7 );

J is O or S;

each R 4 is independently alkylene, alkenylene or a direct bond;

each R 5 is independently hydrogen, alkyl, halo, alkoxy, haloalkyl or hydroxyalkyl;

R 6 and R 7 are selected as follows:

i) R 6 and R 7 are each independently hydrogen or alkyl; or

ii) R 6 and R 7 together with the nitrogen atom on which they are substituted form a 5 or 6-membered heterocyclyl or heteroaryl ring, optionally substituted with one or two halo, alkyl or haloalkyl; and

n is 0-3.

3. The pharmaceutical composition of claim 1 , wherein the compound has formula IV

or an enantiomer or a mixture of enantiomers thereof, or a pharmaceutically acceptable salt, solvate, or hydrate, thereof, wherein:

Q 2 is hydrogen, alkyl, halo, haloalkyl, hydroxyl, alkoxy, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted aryl, —R 4 OR 5 , —R 4 SR 5 , —R 4 N(R 6 )(R 7 ), R 4 OR 4 N(R 6 )(R 7 ) or R 4 OR 4 C(J)N(R 6 )(R 7 );

J is O or S;

each R 4 is independently alkylene, alkenylene or a direct bond;

each R 5 is independently hydrogen, alkyl, haloalkyl or hydroxyalkyl; and

R 6 and R 7 are each independently hydrogen or alkyl.

4. The pharmaceutical composition of claim 1 , wherein the compound is selected from:

2-(3-chloro-4-methylphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(4-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methoxyphenyl)acetamide;

2-(3-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluorophenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-p-tolylacetamide;

2-(3,4-dichlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(2-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-(trifluoromethyl)phenyl)acetamide;

2-(4-tert-butylphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-phenylacetamide

2-(3-chloro-4-fluorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-(trifluoromethylthio)phenyl)acetamide;

2-(2,6-difluorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-o-tolylacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-fluorophenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2-(2-ethoxyphenyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-(trifluoromethoxy)phenyl)acetamide;

2-(3-bromo-4-(trifluoromethoxy)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(3-chloro-4-methoxyphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-m-tolylacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-isopropoxyphenyl)acetamide;

2-(3,4-difluorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-fluorophenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(trifluoromethyl)pyridin-2-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-isopropylphenyl)acetamide;

2-(2,4-dichlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-methoxyphenyl)acetamide;

2-(4-cyclopropylphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(4-chloro-2-fluorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(4-chloro-3-fluorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-fluoro-2-methylphenyl)acetamide;

2-(3-chloro-2-methylphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluoro-2-(trifluoromethyl)phenyl)acetamide;

2-(4-chloro-2-methylphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluoro-2-methylphenyl)acetamide;

2-(4-chloro-2-(trifluoromethyl)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-cyclohexyl-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(4-chloro-2-(trifluoromethoxy)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-methoxyethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-hydroxyethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-(2-methoxyethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-hydroxyethyl)phenyl)acetamide;

2-(3-(dimethylamino)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(piperidin-1-yl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-morpholinophenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluoro-2-isopropoxyphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-(2,2,2-trifluoroethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2-(2-ethoxy-4-fluorophenyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-isopropoxyphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-fluoro-4-isopropoxyphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(morpholinomethyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluoro-2-(2,2,2-trifluoroethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-isopropoxy-2-methylphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-isopropoxy-3-methylphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-fluoro-4-isopropoxyphenyl)acetamide;

2-(3-chloro-4-isopropoxyphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-methyl-4-(trifluoromethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-fluoro-4-(trifluoromethoxy)phenyl)acetamide;

2-(5-chloropyridin-2-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(5-fluoropyridin-2-yl)acetamide;

2-(2,4-difluorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(4-bromophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-(2-methoxyethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(1-hydroxycyclohexyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(1-hydroxycyclopentyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-methyl-4-(trifluoromethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2-(3-ethoxypyridin-2-yl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-methylpyridin-2-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(5-methylpyridin-2-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2-(2-ethoxy-6-fluorophenyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4′-fluorobiphenyl-4-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2-(2-ethoxy-5-fluorophenyl)-2,2-difluoroacetamide;

2-cyclopentyl-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(3-chloro-4-(trifluoromethoxy)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methoxy-2-(trifluoromethyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-(2-hydroxyethoxy)phenyl)acetamide;

2-(4-chloro-2-ethoxyphenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-hydroxyphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(2-(methylamino)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-isopropoxy-2-(trifluoromethyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methylcyclohexyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-isopropoxyethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-hydroxyphenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3 methylpiperazin-1-yl)methyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methyl-2-(trifluoromethyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-(2-methoxyethoxy)ethoxy)phenyl)acetamide;

2-(3-(2-(dimethylamino)ethoxy)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(5-isopropylpyridin-2-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-(methyl sulfonyl)ethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(3-(methyl sulfonyl)propyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-(2-fluoropropan-2-yl)phenyl)acetamide;

2-(1-benzyl-6-oxo-1,6-dihydropyridin-3-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(5-methoxypyridin-2-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(1-methyl-6-oxo-1,6-dihydropyridin-3-yl)acetamide;

2-(5-tert-butylpyridin-2-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(5-cyclopropylpyridin-2-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(5-isopropoxypyridin-2-yl)acetamide;

2-(5-bromopyridin-2-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluoro-2-(trifluoromethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluorocyclohexyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-(methyl sulfonyl)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(methyl sulfonyl)phenyl)acetamide;

2-(2-aminopyrimidin-5-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(5-(trifluoromethylthio)pyridin-2-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-(methylamino)ethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(1-methyl-6-oxo-1,6-dihydropyridazin-3-yl)acetamide;

2-(2-aminopyrimidin-4-yl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(pyrimidin-4-yl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-(piperidin-1-yl)ethoxy)phenyl)acetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(2-morpholinoethoxy)phenyl)acetamide;

2-(3-(2-(4,4-difluoropiperidin-1-yl)ethoxy)phenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(1-methyl-6-oxo-1,6-dihydropyridazin-4-yl)acetamide; and

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(3-(4-methylpiperazin-1-yl)phenyl)acetamide.

5. The pharmaceutical composition of claim 1 , wherein the compound is selected from

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methoxyphenyl)acetamide;

2-(4-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(3-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluorophenyl)acetamide; and

2-(2-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide.

6. The pharmaceutical composition of claim 1 , wherein the compound is N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methoxyphenyl)acetamide.

7. The pharmaceutical composition of claim 1 , wherein the compound is 2-(4-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide.

8. The pharmaceutical composition of claim 1 , wherein the compound is 2-(3-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide.

9. The pharmaceutical composition of claim 1 , wherein the compound is N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluorophenyl)acetamide.

10. The pharmaceutical composition of claim 1 , wherein the compound is 2-(2-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide.

11. A method of treating leukemia comprising administering to a mammal having leukemia a therapeutically effective amount of the pharmaceutical composition of claim 1 .

12. A method of treating leukemia comprising administering to a mammal having leukemia a therapeutically effective amount of the pharmaceutical composition of claim 4 .

13. The method of claim 11 , wherein the leukemia is chronic lymphocytic leukemia, chronic myelocytic leukemia, acute lymphoblastic leukemia or acute myeloid leukemia.

14. The method of claim 11 , wherein the leukemia is an acute myeloid leukemia.

15. The method of claim 11 , wherein the leukemia is relapsed, refractory or resistant to conventional therapy.

16. The method of claim 11 , further comprising administering a therapeutically effective amount of another second active agent or a support care therapy.

17. The method of claim 16 , wherein the other second active agent is a therapeutic antibody that specifically binds to a cancer antigen, hematopoietic growth factor, cytokine, anti-cancer agent, antibiotic, cox-2 inhibitor, immunomodulatory agent, immunosuppressive agent, corticosteroid or a pharmacologically active mutant or derivative thereof.

18. The method of claim 11 , wherein the compound is selected from:

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-methoxyphenyl)acetamide;

2-(4-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

2-(3-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide;

N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoro-2-(4-fluorophenyl)acetamide; and

2-(2-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide.

19. The method of claim 18 , wherein the leukemia is an acute myeloid leukemia.