Synthesis of the Reported Structures for Kealiinines B and C

Syntheses of the reported structures of kealiinines B and C have been executed. An intermolecular electrophile-induced cyclization of a pendant arene on an ene–guanidine affords the tetracyclic, oxidized naphthimidazole cores

Regioselective Base-Mediated Cyclizations of Mono‑<i>N</i>‑acylpropargylguanidines

A regioselective base-mediated cyclization of mono-<i>N</i>-acylpropargylguanidines is reported. A related Ag­(I)-catalyzed hydroamination strategy was recently employed to yield <i>N</i>³-Cbz-protected ene-guanidines, which found utility in the synthesis of naamidine A. Herein, we report the base-catalyzed hydroamination of mono-<i>N</i>-acylpropargylguanidines, which proceeds with the opposite regiochemistry to deliver isomerized <i>N</i>²-acyl-2-aminoimidazoles with broad substrate scope, circumventing the problematic regiospecific acylation of free 2-aminoimidazoles

Synthesis of Naamidine A and Selective Access to N²‑Acyl-2-aminoimidazole Analogues

A short and scalable synthesis of naamidine A, a marine alkaloid with a selective ability to inhibit epidermal growth factor receptor (EGFR)-dependent cellular proliferation, has been achieved. A key achievement in this synthesis was the development of a regioselective hydroamination of a monoprotected propargylguanidine to deliver N³-protected cyclic ene-guanidines. This permits the extension of this methodology to prepare N²-acyl analogues in a fashion that obviates the troublesome acylation of the free 2-aminoimidazoles, which typically yields mixtures of N²<i>-</i> and N²,N²-diacylated products