Synthesis of sterically encumbered 2,4-bis-m-terphenyl-1,3-dichloro-2,4-cyclo-dipnictadiazanes [m-TerNPnCl]2, (Pn = P, As)

Abstract

The reaction of m-terphenyl amine (2,6-bis-(2,4,6-trimethylphenyl)aniline, m-Ter = m-terphenyl = 2,6-bis-(2,4,6-trimethylphenyl)) and ECl₃ (E = P, As) in the presence of different bases (Et₃N, n-BuLi, LDA, DBU) and under different reaction conditions was studied. The reaction with excess Et₃N yielded m-Ter–N(H)–AsCl₂ for E = As, while for E = P m-Ter–N(PCl₂)₂ was formed. m-Ter–N(H)–ECl₂ was obtained in the reaction of m-terphenyl amine with n-BuLi and ECl₃ for E = As and P. Further treatment of m-Ter–N(H)–PCl₂ with Et₃N led to the formation of 1,3-dichloro-cyclo-1,3-diphospha-2,4-diazane, a synthesis protocol which cannot be applied to the analogous arsenic species. 1,3-dichloro-cyclo-1,3-diarsa-2,4-diazane was isolated when DBU was added to m-Ter–N(H)–AsCl₂ at low temperature (−80 °C).