Azide Radical Initiated Ring Opening of Cyclopropenes Leading to Alkenyl Nitriles and Polycyclic Aromatic Compounds

Abstract

We report herein a radical‐mediated amination of cyclopropenes. The transformation proceeds through a cleavage of the three‐membered ring after the addition of an azide radical on the strained double bond and leads to tetrasubstituted alkenyl nitrile derivatives upon loss of N2. With 1,2‐diaryl substituted cyclopropenes, this methodology could be extended to a one‐pot synthesis of highly functionalized polycyclic aromatic compounds (PACs). This transformation allows the synthesis of nitrile‐substituted alkenes and aromatic compounds from rapidly accessed cyclopropenes using only commercially available reagents.

Synthesis of tetrasubstituted alkenyl nitriles via cyanocarbene addition of [1.1.1]propellane

“…Moreover, the reaction proceeded with comparable efficiency in the presence of 2 equivalents of TMSN 3 (entry 7), however, decreasing the amount of TMSN 3 to 1.2 equivalents provided inferior result (entry 8). Extra additives such as catalytic amounts of Fe(acac) 3 25 or CuCl 2 26 did not improve the product yield (entries 9 and 10). Finally, the reaction temperature significantly influenced this reaction, particularly when the reaction was carried out at a lower temperature (0 °C) where only a trace amount of the desired product 3a was found to be formed (Table 1, entry 11).…”