Fluorine substituents have become a widespread and important drug component, their introduction facilitated by the development of safe and selective fluorinating agents. Organofluorine affects nearly all physical and adsorption, distribution, metabolism, and excretion properties of a lead compound. Its inductive effects are relatively well understood, enhancing bioavailability, for example, by reducing the basicity of neighboring amines. In contrast, exploration of the specific influence of carbon-fluorine single bonds on docking interactions, whether through direct contact with the protein or through stereoelectronic effects on molecular conformation of the drug, has only recently begun. Here, we review experimental progress in this vein and add complementary analysis based on comprehensive searches in the Cambridge Structural Database and the Protein Data Bank.

Fluorine in Pharmaceuticals: Looking Beyond Intuition.

/pdf/aryl-aryl-bond-formation-one-century-after-the-discovery-of-1jdyxlkwix.pdf

Aryl-aryl bond formation one century after the discovery of the Ullmann reaction.

The biaryl structural motif is a predominant feature in many pharmaceutically relevant and biologically active compounds. As a result, for over a century 1 organic chemists have sought to develop new and more efficient aryl -aryl bond-forming methods. Although there exist a variety of routes for the construction of aryl -aryl bonds, arguably the most common method is through the use of transition-metalmediated reactions. 2-4 While earlier reports focused on the use of stoichiometric quantities of a transition metal to carry out the desired transformation, modern methods of transitionmetal-catalyzed aryl -aryl coupling have focused on the development of high-yielding reactions achieved with excellent selectivity and high functional group tolerance under mild reaction conditions. Typically, these reactions involve either the coupling of an aryl halide or pseudohalide with an organometallic reagent (Scheme 1), or the homocoupling of two aryl halides or two organometallic reagents. Although a number of improvements have developed the former process into an industrially very useful and attractive method for the construction of aryl -aryl bonds, the need still exists for more efficient routes whereby the same outcome is accomplished, but with reduced waste and in fewer steps. In particular, the obligation to use coupling partners that are both activated is wasteful since it necessitates the installation and then subsequent disposal of stoichiometric activating agents. Furthermore, preparation of preactivated aryl substrates often requires several steps, which in itself can be a time-consuming and economically inefficient process.

http://aether.cmi.ua.ac.be/artikels/Artikels%20Gitte/Artikels/Reviews/Heck-Type-lautens.pdf

Aryl-aryl bond formation by transition-metal-catalyzed direct arylation.

Years of cumulative research can result in the development of a clinically useful drug, providing either a cure for a particular disease or symptomatic relief from a physiological disorder. A lead compound with a desired pharmacological activity may have associated with it undesirable side effects, characteristics that limit its bioavailability, or structural features which adversely influence its metabolism and excretion from the body. Bioisosterism represents one approach used by the medicinal chemist for the rational modification of lead compounds into safer and more clinically effective agents. The concept of bioisosterism is often considered to be qualitative and intuitive.1 The prevalence of the use of bioisosteric replacements in drug design need not be emphasized. This topic has been reviewed in previous years.2-5 The objective of this review is to provide an overview of bioisosteres that incorporates sufficient detail to enable the reader to understand the concepts being delineated. While a few popular examples of the successful use of bioisosteres have been included, the George Patani graduated with a B.Pharm. in 1992 from the College of Pharmaceutical Sciences, Mangalore University at Manipal, India. In 1996, he received his M.S. in Pharmaceutical Science at Rutgers University under the direction of Professor Edmond J. LaVoie. He is presently pursuing graduate studies in pharmaceutics. His current research interests are focused on drug design and controlled drug delivery.

https://www.mch.estranky.sk/file/228/1996chemrev96-3147-76_bioisosterism.pdf

Bioisosterism: A Rational Approach in Drug Design.

DNA topoisomerases are the magicians of the DNA world — by allowing DNA strands or double helices to pass through each other, they can solve all of the topological problems of DNA in replication, transcription and other cellular transactions. Extensive biochemical and structural studies over the past three decades have provided molecular models of how the various subfamilies of DNA topoisomerase manipulate DNA. In this review, the cellular roles of these enzymes are examined from a molecular point of view.

/pdf/cellular-roles-of-dna-topoisomerases-a-molecular-perspective-472dbio7sm.pdf

Cellular roles of DNA topoisomerases: a molecular perspective.

Benzo[j]fluoranthene (B[j]F), trans-4,5-dihydro-4,5-dihydroxy-B[j]F, and trans-9,10-dihydro-9,10-dihydroxy-B[j]F were evaluated for tumorigenic activity in newborn CD1 mice. These dihydrodiols were assayed at doses of 1.10 and 0.275 mumol/mouse. B[j]F and the syn- and anti-diol epoxides derived from these dihydrodiols were evaluated at doses of 1.10, 0.275, and 0.110 mumol/mouse (80 mice/group). trans-4,5-Dihydro-4,5-dihydroxy-B[j]F was more potent than trans-9,10-dihydro-9,10-dihydroxy-B-[j]F in inducing pulmonary tumors in both female and male mice. Administration of 1.10 mumol of trans-4,5-dihydro-4,5-dihydroxy-B[j]F resulted in a 90-92% incidence of pulmonary tumors with an average of 3.6 and 4.2 tumors/mouse among female and male mice, respectively. A similar tumorigenic activity was observed for B[j]F in lung. trans-9,10-Dihydro-9,10-dihydroxy-B[j]F was significantly less tumorigenic (P 0.05) of pulmonary tumors in female or male mice.(ABSTRACT TRUNCATED AT 400 WORDS)

Tumorigenic Activity of the 4,5- and 9,10-Dihydrodiols of Benzo[j]fluoranthene and Their syn- and anti-Diol Epoxides in Newborn Mice

2-Methylbenzo[b]furans and 2-methylbenzo[b]-thiophens were prepared in good yield from the corresponding chloroallyl phenyl ethers and chloroallyl phenyl sulphides, respectively.

Synthesis of 2-methylbenzo[b]furans and 2-methylbenzo[b]thiophens

Seasonal influenza infections are associated with an estimated 250-500 000 deaths annually. Resistance to the antiviral M2 ion-channel inhibitors has largely invalidated their clinical utility. Resistance to neuraminidase inhibitors has also been observed in several influenza A virus (IAV) strains. These data have prompted research on inhibitors that target the cap-snatching endonuclease activity of the polymerase acidic protein (PA). Baloxavir marboxil (Xofluza®), recently approved for clinical use, inhibits cap-snatching endonuclease. Resistance to Xofluza® has been reported in both in vitro systems and in the clinic. An X-ray crystallographic screening campaign of a fragment library targeting IAV endonuclease identified 5-chloro-3-hydroxypyridin-2(1H)-one as a bimetal chelating agent at the active site. We have reported the structure-activity relationships for 3-hydroxypyridin-2(1H)-ones and 3-hydroxyquinolin-2(1H)-ones as endonuclease inhibitors. These studies identified two distinct binding modes associated with inhibition of this enzyme that are influenced by the presence of substituents at the 5- and 6-positions of 3-hydroxypyridin-2(1H)-ones. Herein we report the structure-activity relationships associated with various para-substituted 5-phenyl derivatives of 6-(p-fluorophenyl)-3-hydroxypyridin-2(1H)-ones and the effect of using naphthyl, benzyl, and naphthylmethyl groups as alternatives to the p-fluorophenyl substituent on their activity as endonuclease inhibitors.

Aryl and Arylalkyl Substituted 3-Hydroxypyridin-2(1H)-ones: Synthesis and Evaluation as Inhibitors of Influenza A Endonuclease.

The invention provides compounds of formula I or formula (II), wherein: the bond represented by --- is a single bond or a double bond, and R1-R5, X, and Y have any of the meanings defined in the specification and their pharmaceutically acceptable salts. The invention also provides pharmaceutical compositions comprising a compound of formula (I or II), processes for preparing compounds of formula (I or II), intermediates useful for preparing compounds of formula (I or II), and therapeutic methods for treating cancer and other topoisomerase related conditions using compounds of formula (I or II).

Topoisomerase-targeting agents

Disclosed herein are compounds of formula I: and salts thereof. Also disclosed are compositions comprising compounds of formula I and methods using compounds of formula I.

Edmond J. LaVoie

Papers

Tumorigenic Activity of the 4,5- and 9,10-Dihydrodiols of Benzo[j]fluoranthene and Their syn- and anti-Diol Epoxides in Newborn Mice

Synthesis of 2-methylbenzo[b]furans and 2-methylbenzo[b]thiophens

Aryl and Arylalkyl Substituted 3-Hydroxypyridin-2(1H)-ones: Synthesis and Evaluation as Inhibitors of Influenza A Endonuclease.

Topoisomerase-targeting agents

Bacterial efflux pump inhibitors