Marco Ferrara

Application of Chiral Sulfides to Catalytic Asymmetric Aziridination and Cyclopropanation with In Situ Generation of the Diazo Compound

Imines and alkenes can be converted into the corresponding aziridines and cyclopropanes (see scheme, PTC=phase-transfer catalyst, Ts=toluene-4-sulfonyl) in good yield with moderate to high d.r. and high ee values using tosylhydrazone salts with catalytic quantities of chiral sulfide (5-20 mol %) and metal catalyst (1 mol %). The process is particularly suited to the synthesis of conformationally locked cyclopropyl amino acids, which can now be prepared in only three steps from commercially available material in 100 % ee.

Discovery of MK-5172, a Macrocyclic Hepatitis C Virus NS3/4a Protease Inhibitor.

A new class of HCV NS3/4a protease inhibitors containing a P2 to P4 macrocyclic constraint was designed using a molecular modeling-derived strategy. Building on the profile of previous clinical compounds and exploring the P2 and linker regions of the series allowed for optimization of broad genotype and mutant enzyme potency, cellular activity, and rat liver exposure following oral dosing. These studies led to the identification of clinical candidate 15 (MK-5172), which is active against genotype 1-3 NS3/4a and clinically relevant mutant enzymes and has good plasma exposure and excellent liver exposure in multiple species.

Design and synthesis of bicyclic pyrimidinones as potent and orally bioavailable HIV-1 integrase inhibitors.

HIV integrase is one of the three enzymes encoded by HIV genome and is essential for viral replication, but integrase inhibitors as marketed drugs have just very recently started to emerge. In this study, we show the evolution from the N-methylpyrimidinone structure to bicyclic pyrimidinones. Introduction of a suitably substituted amino moiety modulated the physical-chemical properties of the molecules and conferred nanomolar activity in the inhibition of spread of HIV-1 infection in cell culture. An extensive SAR study led to sulfamide (R)- 22b, which inhibited the strand transfer with an IC50 of 7 nM and HIV infection in MT4 cells with a CIC95 of 44 nM, and ketoamide (S)- 28c that inhibited strand transfer with an IC50 of 12 nM and the HIV infection in MT4 cells with a CIC95 of 13 nM and exhibited a good pharmacokinetic profile when dosed orally to preclinical species.

[2,3]-Sigmatropic rearrangement of allylic sulfur ylides derived from trimethylsilyldiazomethane (TMSD)

Trimethylsilyldiazomethane reacts with allylic sulfides in the presence of catalytic quantities of Rh2(OAc)4 (1 mol%) to give homoallylic sulfides in good yields and with high diastereoselectivity.

Inhibitors of the Hepatitis C Virus NS3 Protease with Basic Amine Functionality at the P3-Amino Acid N-Terminus: Discovery and Optimization of a New Series of P2−P4 Macrocycles

In a follow-up to our recent disclosure of P2-P4 macrocyclic inhibitors of the hepatitis C virus (HCV) NS3 protease (e.g., 1, Chart 1), we report a new but related compound series featuring a basic amine at the N-terminus of the P3-amino acid residue. Replacement of the electroneutral P3-amino acid capping group (which is a feature of almost all tripeptide-like inhibitors of NS3 reported to date) with a basic group is not only tolerated but can result in advantageous cell based potency. Optimization of this new class of P3-amine based inhibitors gave compounds such as 25 and 26 that combine excellent cell based activity with pharmacokinetic properties that are attractive for an antiviral targeting HCV.

Development of 2-pyrrolidinyl-N-methyl pyrimidones as potent and orally bioavailable HIV integrase inhibitors.

A series of 2-pyrrolidinyl-N-methyl pyrimidones HIV integrase inhibitors has been explored leading to the identification of derivative 13, which showed high activity at inhibiting viral replication in cell culture, favorable pharmacokinetic profile in two preclinical species, and an attractive profile against a panel of HIV-integrase mutants.

Enantioselective Synthesis of the Cyclopiazonic Acid Family Using Sulfur Ylides

Abstract A convergent, nine‐step (LLS), enantioselective synthesis of α‐cyclopiazonic acid and related natural products is reported. The route features a) an enantioselective aziridination of an imine with a chiral sulfur ylide; b) a bioinspired (3+2)‐cycloaddition of the aziridine onto an alkene; and c) installation of the acetyltetramic acid by an unprecedented tandem carbonylative lactamization/N−O cleavage of a bromoisoxazole.

Discovery of BI-2545: A Novel Autotaxin Inhibitor That Significantly Reduces LPA Levels in Vivo.

In an effort to find new therapeutic interventions addressing the unmet medical need of patients with idiopathic pulmonary fibrosis, we initiated a program to identify new autotaxin (ATX) inhibitors. Starting from a recently published compound (PF-8380), we identified several highly potent ATX inhibitors with improved pharmacokinetic and safety profiles. Further optimization efforts resulted in the identification of a single-digit nanomolar lead compound (BI-2545) that shows substantial lowering of LPA in vivo and is therefore considered a valuable tool for further studies.