This is a Phase I study that determines a tolerable combination of sorafenib, when given sequentially with cytarabine and clofarabine and determines the feasibility of administering this drug combination in patients with relapsed or refractory hematologic malignancies including acute myeloid leukemia (AML), acute promyelocytic leukemia (APL), acute lymphoblastic leukemia (ALL), infantile leukemia (both either AML and/or ALL). AML with prior myelodysplastic syndrome (MDS), myelodysplastic/myeloproliferative neoplasms, and biphenotypic leukemia.