Vier‐ und fünfgliedrige Phosphorheterocyclen, 52¹⁾ Pentacyclische Diphosphorane aus der Reaktion 2<i>H</i>‐1, 2, 4, 3λ³‐Triazaphosphol/Azodicarbonester

Abstract

Four‐ and Five‐membered Phosphorus Heterocycles, 52 1) Pentacyclic Diphosphoranes from the Reaction 2 H ‐1, 2, 4, 3λ 3 ‐Triazaphosphole/Azodicarboxylic Esters Azodicarboxylic ester react with 2‐methyl‐5‐phenyl‐2 H ‐1, 2, 4, 3λ 3 ‐triazaphosphole ( 1 ) as heterodienes in an oxidative [4 + 1] cycloaddition at the σ 2 ‐phosphorus and a concomitant [2 + 2] dimerization of the supposed intermediate spirocyclic phosphazene 3 . The resulting diphosphoranes 4 may also be synthesized from the dichlorotriazaphosphole dimer 5 and hydrazinedicarboxylic esters 6 .