Employing Photocatalysis for the Design and Preparation of DNA-Encoded Libraries: A Case Study.

This Personal Account describes the authors' foray into DNA-encoded libraries. The article addresses several key aspects of this hit generation technology, from the development of new synthetic methodology to the subsequent conception, design, and delivery of a DNA-encoded library. In particular, we have been engaged in adapting photocatalytic reactions to the idiosyncratic requirements of DNA-encoded chemistry. We have chosen one such methodology, namely a photocatalytic [2+2] cycloaddition reaction, to showcase how we employed property-based computational analyses to guide the selection and validation of building blocks for the production of a library. Ultimately, these novel bond disconnections and design principles led to the assembly of a DNA-encoded library that is composed of structurally diverse compounds within largely desirable property space and, therefore, well positioned to deliver novel chemical matter for drug discovery programs.

Introduction of a Crystalline, Shelf-Stable Reagent for the Synthesis of Sulfur(VI) Fluorides.

The design, synthesis, and application of [4-(acetylamino)phenyl]imidodisulfuryl difluoride (AISF), a shelf-stable, crystalline reagent for the synthesis of sulfur(VI) fluorides, is described. The utility of AISF is demonstrated in the synthesis of a diverse array of aryl fluorosulfates and sulfamoyl fluorides under mild conditions. Additionally, a single-step preparation of AISF was developed that installed the bis(fluorosulfonyl)imide group on acetanilide utilizing an oxidative C-H functionalization protocol.

Driving external chemistry optimization via operations management principles.

Confronted with the need to significantly raise the productivity of remotely located chemistry CROs Pfizer embraced a commitment to continuous improvement which leveraged the tools from both Lean Six Sigma and queue management theory to deliver positive measurable outcomes. During 2012 cycle times were reduced by 48% by optimization of the work in progress and conducting a detailed workflow analysis to identify and address pinch points. Compound flow was increased by 29% by optimizing the request process and de-risking the chemistry. Underpinning both achievements was the development of close working relationships and productive communications between Pfizer and CRO chemists.

Structure-based design, synthesis, and biological evaluation of irreversible human rhinovirus 3C protease inhibitors. 8. Pharmacological optimization of orally bioavailable 2-pyridone-containing peptidomimetics.

The optimization of the pharmacokinetic performance of various 2-pyridone-containing human rhinovirus (HRV) 3C protease (3CP) inhibitors following oral administration to either beagle dogs or CM-monkeys is described. The molecules described in this work are composed of a 2-pyridone-containing peptidomimetic binding determinant and an alpha,beta-unsaturated ester Michael acceptor moiety which forms an irreversible covalent adduct with the active site cysteine residue of the 3C enzyme. Modification of the ester contained within these compounds is detailed along with alteration of the P(2) substituent present in the peptidomimetic portion of the inhibitors. The pharmacokinetics of several inhibitors in both dogs and monkeys are described (7 h plasma concentrations after oral administration) along with their human plasma stabilities, stabilities in incubations with human, dog, and monkey microsomes and hepatocytes, Caco-2 permeabilities, and aqueous solubilities. Compounds containing an alpha,beta-unsaturated ethyl ester fragment and either an ethyl or propargyl P(2) moiety displayed the most promising combination of 3C enzyme inhibition (k(obs)/[I] 170 000-223 000 M(-1) s(-1)), antiviral activity (EC(50) = 0.047-0.058 microM, mean vs seven HRV serotypes), and pharmacokinetics following oral administration (7 h dog plasma levels = 0.248-0.682 microM; 7 h CM-monkey plasma levels = 0.057-0.896 microM).

Structure-based design, synthesis, and biological evaluation of irreversible human rhinovirus 3C protease inhibitors. 6. Structure-activity studies of orally bioavailable, 2-pyridone-containing peptidomimetics.

The structure-based design, chemical synthesis, and biological evaluation of various 2-pyridone-containing human rhinovirus (HRV) 3C protease (3CP) inhibitors are described. These compounds are comprised of a peptidomimetic binding determinant and a Michael acceptor moiety, which forms an irreversible covalent adduct with the active site cysteine residue of the 3C enzyme. The 2-pyridone-containing inhibitors typically display improved 3CP inhibition properties relative to related peptide-derived molecules along with more favorable antiviral properties. The cocrystal structure of one pyridone-derived 3CP inhibitor complexed with HRV-2 3CP is also described along with certain ab initio conformation analyses. Optimization of the 2-pyridone-containing compounds is shown to provide several highly active 3CP inhibitors (k(obs)/[I] > 500,00 M(-1) s(-1)) that function as potent antirhinoviral agents (EC(50) = <0.05 microM) against multiple virus serotypes in cell culture. One 2-pyridone-containing 3CP inhibitor is shown to be bioavailable in the dog after oral dosing (F = 48%).

Construction of substituted cyclohexanones by reductive cyclization of 7-oxo-2,8-alkadienyl esters.

[reaction: see text] Cyclization of 7-oxo-2,8-alkadienyl esters upon reaction with triphenylphosphinecopper hydride hexamer stereoselectively yields substituted cyclohexanones having a cis relationship of carbon side chains at C2 and C3. This cyclohexanone construction is particularly useful for preparing 4-alkoxy- or 4-siloxy-2,3-disubstituted cyclohexanones, in which instance stereoselection is > or = 20:1.