Mevashuntin, a novel metabolite produced by inhibition of the mevalonate pathway in Streptomyces prunicolor

Epoxides as Alkylating Reagents for the Catellani Reaction

We report a cooperative catalytic system comprising a Pd^II complex, XPhos, and the potassium salt of 5-norbornene-2-carboxylic acid that enables the use of epoxides as alkylating reagents in the Catellani reaction, thereby expanding the existing paradigm of this powerful transformation. The potassium salt of inexpensive 5-norbornene-2-carboxylic acid acts as both mediator and base in the process. This mild, chemoselective, scalable, and atom-economical protocol is compatible with a wide variety of readily available functionalized aryl iodides and epoxides, as well as terminating olefins. The resulting products undergo facile oxa-Michael addition to furnish ubiquitous isochroman scaffolds.

Naturally Occurring Nitrogen–Sulfur Compounds. The Benzothiazole Alkaloids

Several alkaloids contain both nitrogen and sulfur, and a subset of these interesting terrestrial and marine natural products – the benzothiazoles – forms the subject of the present short review. Benzothiazole alkaloids are relatively rare in Nature, but they range in structural complexity from benzothiazole itself and simple derivatives thereof, through the well-known firefly luciferin, to more complex molecules such as the thiazo-rifamycins and the dercitin-kuanoniamine family. Although the biosynthesis of benzothiazoles has not been studied in many cases, the evidence suggests that they are derived from cysteine addition to benzoquinone derivatives followed by ring contraction of the resulting benzothiazine adducts. The review also highlights the fact that little synthetic work has been done on benzothiazole-containing natural products.