Allenyl and Divinyl Phosphines, Arsines, and Stibines as Potential Precursors of the Corresponding 1- and 2-Phospha, 1- and 2-Arsa, and 1- and 2-Stiba Dienes

The base-induced rearrangement of divinylphosphine led to the corresponding 3-phospha-1,3-pentadiene, which is sufficiently stable to be detected at room temperature by 31 P NMR spectroscopy. This diene was trapped by addition of 2-propanethiol to the reaction mixture. Under similar conditions, the transient 1-phospha-1,3-butadiene and 3-arsa-1,3-pentadiene were chemically trapped. Divinylstibine and allenylstibine, both new compounds and potential precursors of stibadienes, were also prepared.