Bioinspired Total Synthesis of Marine Anti-Cancer Meroterpenoids Dysideanone B and Dysiherbol A and Structure Revision of Dysiherbol A

Our recent progress on the total synthesis of marine anti-cancer sesquiterpene quinone/hydroquinone dysideanone B and dysiherbol A was briefly highlighted. This success relied on some key transformations. The union of the terpene and quinone/hydroquinone moieties was realized through a site and stereoselective α-position alkylation of Wieland–Miescher ketone derivative with a bulky benzyl bromide. The 6/6/6/6-tetracycle of dysideanone B was constructed using an intramolecular radical cyclization and the 6/6/5/6-fused core structure of dysiherbol A was forged by an intramolecular Heck reaction, respectively. The possible origin of ethoxy group in dysideanone B was revealed by mimicking the isolation conditions at a late-stage. The structure of dysiherbol A was revised through the total synthesis of this natural product. Schmalz’s synthesis of dysiherbol A was also included.

Concise synthesis and in vitro anticancer activity of benzo[g][1]benzopyrano[4,3-b]indol-6(13H)-ones (BBPIs), topoisomerase I inhibitors based on the marine alkaloid lamellarin

Benzo[g][1]benzopyrano[4,3-b]indol-6(13H)-ones (BBPIs) are potent anticancer compounds having unique BBPIs ring system designed on the basis of the marine natural product lamellarin D. In this study, we describe an alternative synthesis of a 2-demethoxy series of BBPIs, employing van Leusen pyrrole synthesis and an intramolecular Heck reaction as the key reactions. Cytotoxicity of the derivatives against several cancer and normal cell lines is reported.

Recent developments in asymmetric Heck type cyclization reactions for constructions of complex molecules

This review summarizes the recent developments in the asymmetric intramolecular Heck reaction and carbometallation-initiated cascade transformations including Ni-catalyzed processes with literature coverage mainly extending from 2016 to 2021.

Novel ultra-small Pd NPs on SOS spheres: a new catalyst for domino intramolecular Heck and intermolecular Sonogashira couplings

We report a novel catalyst Pd/SOS that catalyzes the dual C–C bond forming coupling of an iodoarene moiety with an internal alkene and an external alkyne via an intramolecular Heck reaction, followed by an intermolecular Sonogashira reaction, respectively.

Chemoenzymatic Total Synthesis of (+)-10-Keto-Oxycodone from Phenethyl Acetate

The total synthesis of (+)-10-keto-oxycodone was attained from phenethyl acetate in a stereoselective manner. Absolute stereochemistry was established via enzymatic dihydroxylation of phenethyl acetate with the recombinant strain JM109 (pDTG601A) that furnished the corresponding cis-cyclohexadienediol whose configuration corresponds to the absolute stereochemistry of the ring C of (+)-10-keto-oxycodone. Intramolecular Heck reaction was utilized to establish the quaternary carbon at C-13, along with the dibenzodihydrofuran functionality. The C-14 hydroxyl and C-10 ketone were installed via SmI2-mediated radical cyclization, and oxidation of a benzylic alcohol (obtained from an intermediate nitrate azide), respectively. The synthesis of (+)-10-keto-oxycodone was completed in a total of 14 operations (21 steps) and an overall yield of ~2%. Experimental and spectral data are provided for key intermediates and new compounds.

Dibenzo[b,e]azepin-6-ones and Seven-Membered Sultam Derivatives: Convenient Synthesis via Palladium-Catalyzed Regioselective Intra­molecular Heck Reaction and Application towards Drug-Like Small Molecules

A new, convenient synthesis of dibenzo[b,e]azepin-6-ones and seven-membered sultam derivatives have been envisaged via Pd-catalyzed regioselective intramolecular Heck reaction of the corresponding easily accessible precursors. This protocol has been successfully implemented to synthesize N-methyldarenzepine in four steps and in good yield. Moreover, one of the intermediates has been utilized for the synthesis of a new analogue of darenzepine. Preliminary modeling studies were performed to investigate the binding potential to muscarinic acetylcholine receptor (M4).