6‑Aroylated Phenanthridines via Base Promoted Homolytic Aromatic Substitution (BHAS)

Readily accessible 2-isocyanobiphenyls react with aromatic aldehydes via base promoted homolytic aromatic substitution (BHAS) to give 6-aroylated phenanthridines. Reactions occur via addition of acyl radicals to the isonitrile functionality and subsequent intramolecular BHAS of the intermediate imidoyl radicals. Initiation of the radical chain reaction is best achieved with small amounts of FeCl₃ (0.4 mol %), and the commercially available and cheap <i>t</i>BuOOH is used as the oxidant

6‑Phosphorylated Phenanthridines from 2‑Isocyanobiphenyls via Radical C–P and C–C Bond Formation

A C–P bond and a C–C bond are formed in the synthesis of 6-phosphorylated phenanthridines starting with readily prepared 2-isocyanobiphenyls and commercially available P-radical precursors. The radical cascade reaction comprises addition of an oxidatively generated P-centered radical to the isonitrile functionality and subsequent homolytic aromatic substitution. Various 6-phosphorylated phenanthridines are formed in moderate to excellent yield. In contrast to the currently intensively investigated direct arene phosphorylation, the arene core is constructed with concomitant phosphorylation using this approach

6‑Phosphorylated Phenanthridines from 2‑Isocyanobiphenyls via Radical C–P and C–C Bond Formation

A C–P bond and a C–C bond are formed in the synthesis of 6-phosphorylated phenanthridines starting with readily prepared 2-isocyanobiphenyls and commercially available P-radical precursors. The radical cascade reaction comprises addition of an oxidatively generated P-centered radical to the isonitrile functionality and subsequent homolytic aromatic substitution. Various 6-phosphorylated phenanthridines are formed in moderate to excellent yield. In contrast to the currently intensively investigated direct arene phosphorylation, the arene core is constructed with concomitant phosphorylation using this approach