Current Progresses and Trends in the Development of Progesterone Receptor Modulators.

The progesterone receptor (PR) is a ligand-activated steroid receptor in the nuclear receptor (NR) superfamily of transcription factor. Besides gynecological and obstetrical indications, the involvement/mechanism of PR in many other diseases, such as oncology, neurology, immunology, etc. has been revealed and studied in recent decades. Therapeutic agents that selectively activate or inhibit PR have been developed. PR agonists have generally been used in oral contraception and postmenopausal hormone replacement therapy (HRT), typically in combination with estrogens. PR antagonists and selective PR modulators (SPRMs) can be useful therapies for hormone dependent breast and prostate cancers, nonmalignant chronic conditions such as fibroids, and endometriosis. This review provides an overview and detailed discussions about the recent development of chemical structures of the PR ligands, their structural characteristics (particularly those contributing to their activity and selectivity), in vitro/in vivo studies and clinical trial outcomes, and the synthetic methodologies.

Homologation Reaction of Ketones with Diazo Compounds.

This review covers the addition of diazo compounds to ketones to afford homologated ketones, either in the presence or in the absence of promoters or catalysts. Reactions with diazoalkanes, aryldiazomethanes, trimethylsilyldiazomethane, α-diazo esters, and disubstituted diazo compounds are covered, commenting on the complex regiochemistry of the reaction and the nature of the catalysts and promoters. The recent reports on the enantioselective version of ketone homologation reactions are gathered in one section, followed by reports on the use of cyclic ketones ring expansion in total synthesis. Although the first reports of this reaction appeared in the literature almost one century ago, the recent achievements, in particular, for the asymmetric version, forecast the development of new breakthroughs in the synthetically valuable field of diazo chemistry.

Synthesis and Biological Evaluation of Pentacycloundecylamines and Triquinylamines as Voltage-Gated Calcium Channel Blockers.

Preclinical studies for neurodegenerative diseases have shown a multi-targeted approach to be successful in the treatment of these complex disorders with several pathoetiological pathways. Polycyclic compounds, such as NGP1-01 (7a), have demonstrated the ability to target multiple mechanisms of the complex etiology and are referred to as multifunctional compounds. These compounds have served as scaffolds with the ability to attenuate Ca(2+) overload and excitotoxicity through several pathways. In this study, our focus was on mitigating Ca(2+) overload through the L-type calcium channels (LTCC). Here, we report the synthesis and biological evaluation of several novel polycyclic compounds. We determined the IC50 values for both the pentacycloundecylamines and the triquinylamines by means of a high-throughput fluorescence calcium flux assay utilizing Fura-2/AM. The potential of these compounds to offer protection against hydrogen peroxide-induced cell death was also evaluated. Overall, 8-benzylamino-8,11-oxapentacyclo[5.4.0.0(2,6) .0(3,10) .0(5,9) ]undecane (NGP1-01, 7a) had the most favorable pharmacological profile with an IC50 value of 86 µM for LTCC inhibition and significant reduction of hydrogen peroxide-induced cell death. In general, the triquinylamines were more active as LTCC blockers than the oxa-pentacycloundecylamines. The aza-pentacycloundecylamines were potent LTCC inhibitors, with 8-hydroxy-N-phenylethyl-8,11-azapentacyclo[5.4.0.0(2,6) .0(3,10) .0(5,9) ]undecane (8b) also able to offer significant protection in the cell viability assays.

Donor- and/or acceptor-substituted expanded radialenes: theory, synthesis, and properties.

The synthesis of donor- (D) and/or acceptor (A)-expanded [4]radialenes has been developed on the basis of readily available dibromoolefin (7), tetraethynylethene (10 and 20), and vinyl triflate (12) building blocks. The successful formation of D/A radialenes relies especially on (1) effective use of a series alkynyl protecting groups, (2) Sonogashira cross-coupling reactions, and (3) the development of ring closing reactions to form the desired macrocyclic products. The expanded [4]radialene products have been investigated by spectroscopic (UV-vis absorption and emission) and quantum chemical computational methods (density functional theory and time dependent DFT). The combined use of theory and experiment provides a basis to evaluate the extent of D/A interactions via the cross-conjugated radialene framework as well as an interpretation of the origin of D/A interactions at an orbital level.

Toward lead-oriented synthesis: one-pot version of Castagnoli condensation with nonactivated alicyclic anhydrides.

One-pot variation of Castagnoli condensation, that is, reaction of cyclic anhydrides, amines, and aldehydes, has been developed as a combinatorial approach to 1,2-disubstituted 5-oxopyrrolidine- and 6-oxopiperidine-3-carboxylic acids, as well as their benzo-analogues. Utility of the method to multigram preparation of building blocks and synthetic intermediates was also demonstrated. The final products are obtained in high yields and diastereoselectivity. The method fits well in the concept of lead-oriented synthesis; in particular, it can be used for the design of lead-like compound libraries, even if the strictest cut-offs are applied to the physicochemical properties of their members.

E pluribus unum: isolation, structure determination, network analysis and DFT studies of a single metastable structure from a shapeshifting mixture of 852 bullvalene structural isomers.

Bullvalene is an organic molecule that spontaneously undergoes Cope rearrangements, resulting in a reconfiguration of its carbon framework. During our study of oligosubstituted bullvalenes, which are structurally dynamic shapeshifting molecules, we found that we could isolate one metastable isomer from the interconverting population of 1680 constitutional isomers (852 structures if enantiomeric pairs are counted once). The preferential formation and unexpected stability of this isomer led to many questions, which we have addressed in this report. (1) What is its structure? (2) How many rearrangements are required to form this isomer from the initial bullvalene structure? (3) Why is it the preferred isomer? (4) What is the role of the substituents in its energetic preference? Our answers required synthesis, HPLC isolation, NMR characterizations, network construction and analysis, and computational (DFT) studies. The results of these efforts revealed the remarkable interconversion network of bullvalene rearrangements. The formation of this metastable isomer is preferred by both thermodynamic and kinetic factors and the ester substituent amplifies the energy difference between various structural isomers of oligosubstituted bullvalenes. The shapeshifting nature of oligosubstituted bullvalene is a useful and unusual property that has many potential applications. Insights into their rearrangements, energy landscape and substituent effect will be important knowledge for the development of these molecules towards materials, sensors and biologically active compounds.

Stereoselective α-quaternization of 3-methoxycycloalk-2-enones via 1,4-diastereoinduction of alkoxy dienolates.

The alkylation of dienolates generated from 3-methoxycycloalk-2-enones having a 3'-hydroxyl alkenyl chain provides the corresponding quaternized cycloalkenones in a highly diastereoselective manner. The high degree of stereocontrol in the α-quaternization possibly implies intervention of a rigid chelating transition state that allows an efficient 1,4-asymmetric induction to take place.

Surface functionalization of metal-organic polyhedron for homogeneous cyclopropanation catalysis.

A super-paddlewheel (comprised of two paddlewheels) metal-organic polyhedron (MOP) containing surface hydroxyl groups was synthesized and characterized. Condensation reactions with linear alkyl anhydrides lead to new MOPs with enhanced solubility. As a result, the surface-modified MOP 4 was demonstrated as a homogeneous Lewis-acid catalyst.

The importance of stereochemistry on the actions of vitamin D.

The seco-steroid hormone 1α,25-dihydroxyvitamin D(3) [1α,25(OH)(2)D(3)] is the most potent natural metabolite of vitamin D(3) and regulates primarily calcium and phosphate homeostasis, but also as a regulator of specific differentiation and of the immune system. Most, if not all, of the biological actions of 1α,25(OH)(2)D(3) are mediated through its specific receptor, the vitamin D receptor (VDR), which is a member of the nuclear receptor superfamily acting as a ligand-dependent transcription factor with coactivators. 1α,25(OH)(2)D(3) has significant therapeutic potential in the treatment of osteoporosis, rickets, secondary hyperparathyroidism, psoriasis, and renal osteodystrophy. However, the use of 1α,25(OH)(2)D(3) itself is limited because it induces significant hypercalcemia. Vitamin D is a highly flexible molecule and a very large number of analogs have been synthesized by industry and academia in an attempt to provide beneficial therapeutic agents with low calcemic activity. Chemical modifications of every portion of the vitamin D(3) molecule (the A, C, and D rings, the 17ß-aliphatic side chain, and the 5,6,7,8-diene moiety) have been reported, with the most of the interesting analogs resulting from a combination of several modifications. The three-dimensional structure of both rat and human VDR-LBD have provided significant information for our understanding of the structure-function relationship (SFR) of vitamin D and some synthetic analogs. In this review, we focus on the current understanding of the relationship between selected stereochemical modifications of key structural components (i.e. A-ring, CD-ring and Side-chain) of the 1α,25(OH)(2)D(3) molecule and their effect on biological potency and selectivity. Based on current information, suggestions for the structure-based design of therapeutically valuable vitamin D analogs will conclude the review.

New alicyclic musks: the fourth generation of musk odorants.

Musk odorants are one of the most important classes of fragrances in perfumery because they impart sensuality to perfume-oil compositions. Among the three well-known classes of musks, a new and very exciting generation of musk odorants, the so-called alicyclic musks, was discovered recently, of which Helvetolide (2) and Romandolide (3) are the most popular representatives so far. To find new, structurally related alicyclic musks, we have synthesized a library of 114 unique alicyclic molecules with modified cyclohexyl moieties. The olfactory properties of all compounds were evaluated to identify the structural requirements to be met for a musk odorant.