Discovery of XL413, a potent and selective CDC7 inhibitor.

CDC7 is a serine/threonine kinase that has been shown to be required for the initiation and maintenance of DNA replication. Up-regulation of CDC7 is detected in multiple tumor cell lines, with inhibition of CDC7 resulting in cell cycle arrest. In this paper, we disclose the discovery of a potent and selective CDC7 inhibitor, XL413 (14), which was advanced into Phase 1 clinical trials.

Discovery of a novel series of potent and orally bioavailable phosphoinositide 3-kinase γ inhibitors.

The phosphoinositide 3-kinases (PI3Ks) have been linked to an extraordinarily diversified group of cellular functions making these enzymes compelling targets for the treatment of disease. A large body of evidence has linked PI3Kγ to the modulation of autoimmune and inflammatory processes making it an intriguing target for drug discovery. Our high-throughput screening (HTS) campaign revealed two hits that were nominated for further optimization studies.

Discovery of a new class of glucosylceramide synthase inhibitors.

A novel series of potent inhibitors of glucosylceramide synthase are described. The optimization of biochemical and cellular potency as well as ADME properties led to compound 23c. Broad tissue distribution was obtained following oral administration to mice.

Discovery of novel sphingosine kinase-1 inhibitors. Part 2.

Building on our initial work, we have identified additional novel inhibitors of sphingosine kinase-1 (SK1). These new analogs address the shortcomings found in our previously reported compounds. Inhibitors 51 and 54 demonstrated oral bioavailability in a rat PK study.

Discovery of novel sphingosine kinase 1 inhibitors.

Sphingosine kinase 1 (SK1) is an important enzyme that regulates the balance between ceramide and sphingosine-1-phosphate (S1P). Potent and novel SK1 inhibitors (6ag, 9ab and 12aa) have been discovered through a series of modifications of sphingosine (1), the substrate of this enzyme.

A robust platform for the synthesis of new tetracycline antibiotics.

Tetracyclines and tetracycline analogues are prepared by a convergent, single-step Michael-Claisen condensation of AB precursor 1 or 2 with D-ring precursors of wide structural variability, followed by removal of protective groups (typically in two steps). A number of procedural variants of the key C-ring-forming reaction are illustrated in multiple examples. These include stepwise deprotonation of a D-ring precursor followed by addition of 1 or 2, in situ deprotonation of a D-ring precursor in mixture with 1 or 2, and in situ lithium-halogen exchange of a benzylic bromide D-ring precursor in the presence of 1 or 2, followed by warming.

Applications of asymmetric hydrosilylations mediated by catalytic (DTBM-SEGPHOS)CuH.

[reaction: see text] Several aryl ketone precursors useful in the synthesis of known physiologically active compounds have been reduced to the corresponding nonracemic alcohols. The previously reported combination of a catalytic quantity of (R)-(-)-DTBM-SEGPHOS-ligated CuH and stoichiometric PMHS is shown to be very effective in these asymmetric hydrosilylations.

Asymmetric hydrosilylation of aryl ketones catalyzed by copper hydride complexed by nonracemic biphenyl bis-phosphine ligands.

When complexed by selected ligands in either the BIPHEP or the SEGPHOS series, CuH is an extremely reactive catalyst capable of effecting asymmetric hydrosilylations of aromatic ketones at temperatures between -50 and -78 degrees C. Inexpensive silanes serve as stoichiometric sources of hydride. Substrate-to-ligand ratios exceeding 100000:1 have been documented.

Copper(I) hydride-catalyzed asymmetric hydrosilylation of heteroaromatic ketones.

In situ generation of CuH ligated by Takasago's new nonracemic ligand, DTBM-SEGPHOS, leads to an especially reactive reagent capable of effecting asymmetric hydrosilylation of heteroaromatic (H) ketones under very mild conditions. PMHS serves as an inexpensive source of hydride. Substrate-to-ligand ratios on the order of 2000:1 are employed.