Highly Regioselective Syntheses of Substituted Triphenylenes from 1,2,4-Trisubstituted Arenes via a Co-Catalyzed Intermolecular Alkyne Cyclotrimerization

Herein, we report the development of a new method for the syntheses of substituted triphenylenes from the corresponding 1,2,4-trisubstituted arenes, which were themselves generated in a highly regioselective manner according to an intermolecular alkyne cyclotrimerization reaction that was catalyzed by a novel Co–TMTU complex. This highly regioselective reaction for the formation of 1,2,4-trisubstituted arenes will be a valuable addition to the plethora of tools already available to synthetic chemists and encourage further mechanistic studies of this important alkyne trimerization process

General Synthetic Approach to Functionalized Dihydrooxepines

A three-step sequence to access functionalized 4,5-dihydrooxepines from cyclohexenones has been developed. This approach features a regioselective Baeyer–Villiger oxidation and subsequent functionalization via the corresponding enol phosphate intermediate

Synthesis and Biological Investigation of Δ¹²-Prostaglandin J₃ (Δ¹²-PGJ₃) Analogues and Related Compounds

A series of Δ¹²-prostaglandin J₃ (Δ¹²-PGJ₃) analogues and derivatives were synthesized employing an array of synthetic strategies developed specifically to render them readily available for biological investigations. The synthesized compounds were evaluated for their cytotoxicity against a number of cancer cell lines, revealing nanomolar potencies for a number of them against certain cancer cell lines. Four analogues (<b>2</b>, <b>11</b>, <b>21</b>, and <b>27</b>) demonstrated inhibition of nuclear export through a covalent addition at Cys528 of the export receptor Crm1. One of these compounds (i.e., <b>11</b>) is currently under evaluation as a potential drug candidate for the treatment of certain types of cancer. These studies culminated in useful and path-pointing structure–activity relationships (SARs) that provide guidance for further improvements in the biological/pharmacological profiles of compounds within this class

Streamlined Total Synthesis of Uncialamycin and Its Application to the Synthesis of Designed Analogues for Biological Investigations

From the enediyne class of antitumor antibiotics, uncialamycin is among the rarest and most potent, yet one of the structurally simpler, making it attractive for chemical synthesis and potential applications in biology and medicine. In this article we describe a streamlined and practical enantioselective total synthesis of uncialamycin that is amenable to the synthesis of novel analogues and renders the natural product readily available for biological and drug development studies. Starting from hydroxy- or methoxyisatin, the synthesis features a Noyori enantioselective reduction, a Yamaguchi acetylide-pyridinium coupling, a stereoselective acetylide-aldehyde cyclization, and a newly developed annulation reaction that allows efficient coupling of a cyanophthalide and a <i>p</i>-methoxy semiquinone aminal to forge the anthraquinone moiety of the molecule. Overall, the developed streamlined synthesis proceeds in 22 linear steps (14 chromatographic separations) and 11% overall yield. The developed synthetic strategies and technologies were applied to the synthesis of a series of designed uncialamycin analogues equipped with suitable functional groups for conjugation to antibodies and other delivery systems. Biological evaluation of a select number of these analogues led to the identification of compounds with low picomolar potencies against certain cancer cell lines. These compounds and others like them may serve as powerful payloads for the development of antibody drug conjugates (ADCs) intended for personalized targeted cancer therapy