Rh(III)-Catalyzed C-H Activation/Annulation of Benzohydroxamates and 2-Imidazolones: Access to Urea-Fused-Dihydroisoquinolone Scaffolds Reminiscent of Pyrrole Alkaloid Natural Products.

A Rh(III)-catalyzed C-H activation/annulation with an imidazolone as alkene partner is reported to access dihydroisoquinolone-fused imidazolin-2-ones. These bicycles are reminiscent of scaffolds belonging to the pyrrole alkaloid family of natural products. This approach facilitates construction of a variety of urea-fused dihydroisoquinolone scaffolds including heterocyclic moieties.

Natural product scaffolds as inspiration for the design and synthesis of 20S human proteasome inhibitors.

The 20S proteasome is a valuable target for the treatment of a number of diseases including cancer, neurodegenerative disease, and parasitic infection. In an effort to discover novel inhibitors of the 20S proteasome, many reseaarchers have looked to natural products as potential leads for drug discovery. The following review discusses the efforts made in the field to isolate and identify natural products as inhibitors of the proteasome. In addition, we describe some of the modifications made to natural products in order to discover more potent and selective inhibitors for potential disease treatment.

Substrate Controlled Regioselective Bromination of Acylated Pyrroles Using Tetrabutylammonium Tribromide (TBABr3).

Electrophilic bromination of pyrroles bearing carbonyl substituents at C-2 typically results in a mixture of the 4- and 5-brominated species, generally favoring the 4-position. Herein, we describe a substrate-controlled regioselective bromination in which tetra-butyl ammonium tribromide (TBABr3) reacts with pyrrole-2-carboxamide substrates to yield the 5-brominated species as the predominant (up to >10:1) product.