Reaction of aluminum halide σ complexes of cyclobutadienes with phosphonous dichlorides. Preparation of phospholium salts and phosphole oxides.

Investigations on non-classical silylium ions leading to a cyclobutenyl cation

“…S-60†). A similar adduct between Me 4 C 4 –AlCl 3 and PPhCl 2 was already proposed as an intermediate in the synthesis of phosphole oxides 33. Due to the syn -conformation of the DMAP and Me 3 Si moieties it seemed possible to remove both of them in the form of [DMAP–SiMe 3 ] + under the release of Me 4 C 4 by gentle warming/heating.…”