Powerful Approach to Heterocyclic Skeletal Diversity by Sequential Three-Component Reaction of Amines, Isothiocyanates, and 1,2-Diaza-1,3-dienes

By highly efficient, one-pot, three-component reactions, combining one set of 1,2-diaza-1,3-dienes (DDs), primary amines, and isothiocyanates in a different sequential order of addition, heterocyclic skeletal diversity can be achieved. The key feature discriminating the different heterocyclic core formation is the availability of the <i>N</i> or <i>S</i> heteronucleophile to give the first Michael addition step affording regioselective substituted 2-thiohydantoins or 2-iminothiazolidinones. The hydrazone or enehydrazino side chain at the 5-position of both heterocycles represents a valuable functionality to reach novel 5-hydroxyethylidene derivatives difficult to obtain by other methods

Divergent Approach to Thiazolylidene Derivatives: A Perspective on the Synthesis of a Heterocyclic Skeleton from β‑Amidothioamides Reactivity

Herein we report a domino protocol able to reach regioselectively thiazolylidene systems by combining the reactive peculiarities of both β-amidothioamides (ATAs) and 1,2-diaza-1,3-dienes (DDs). Depending on the reaction conditions and/or the nature of the residue at C4 of the heterodiene system, ATAs can act as hetero-mononucleophiles or hetero-dinucleophiles in the diversified thiazolylidene ring assembly

Side-Chain Modified Ergosterol and Stigmasterol Derivatives as Liver X Receptor Agonists

A series of stigmasterol and ergosterol derivatives, characterized by the presence of oxygenated functions at C-22 and/or C-23 positions, were designed as potential liver X receptor (LXR) agonists. The absolute configuration of the newly created chiral centers was definitively assigned for all the corresponding compounds. Among the 16 synthesized compounds, <b>21</b>, <b>27</b>, and <b>28</b> were found to be selective LXRα agonists, whereas <b>20</b>, <b>22</b>, and <b>25</b> showed good selectivity for the LXRβ isoform. In particular, <b>25</b> showed the same degree of potency as 22<i>R</i>-HC (<b>3</b>) at LXRβ, while it was virtually inactive at LXRα (EC₅₀ = 14.51 μM). Interestingly, <b>13</b>, <b>19</b>, <b>20</b>, and <b>25</b> showed to be LXR target gene-selective modulators, by strongly inducing the expression of <i>ABCA1</i>, while poorly or not activating the lipogenic genes <i>SREBP1</i> and <i>SCD1</i> or <i>FASN</i>, respectively

Novel Analgesic/Anti-Inflammatory Agents: 1,5-Diarylpyrrole Nitrooxyalkyl Ethers and Related Compounds as Cyclooxygenase‑2 Inhibiting Nitric Oxide Donors

A series of 3-substituted 1,5-diarylpyrroles bearing a nitrooxyalkyl side chain linked to different spacers were designed. New classes of pyrrole-derived nitrooxyalkyl inverse esters, carbonates, and ethers (<b>7</b>–<b>10</b>) as COX-2 selective inhibitors and NO donors were synthesized and are herein reported. By taking into account the metabolic conversion of nitrooxyalkyl ethers (<b>9</b>, <b>10</b>) into corresponding alcohols, derivatives <b>17</b> and <b>18</b> were also studied. Nitrooxy derivatives showed NO-dependent vasorelaxing properties, while most of the compounds proved to be very potent and selective COX-2 inhibitors in in vitro experimental models. Further in vivo studies on compounds <b>9a</b>,<b>c</b> and <b>17a</b> highlighted good anti-inflammatory and antinociceptive activities. Compound <b>9c</b> was able to inhibit glycosaminoglycan (GAG) release induced by interleukin-1β (IL-1β), showing cartilage protective properties. Finally, molecular modeling and ¹H- and ¹³C-NMR studies performed on compounds <b>6c</b>,<b>d</b>, <b>9c</b>, and <b>10b</b> allowed the right conformation of nitrooxyalkyl ester and ether side chain of these molecules within the COX-2 active site to be assessed