Diphospholyl anion

P. B. Hitchcock, J. A. Johnson, and J. F. Nixon, Syntheses and Structures of Diruthenium Triple-Decker Complexes with Bridging 1,2,4-Triphospholyl and l-Arsa-3,4-Diphospholyl Anions, Organometallics 14, 4382-4389 (1995). 

The heterocycles that are discussed in this chapter are 1,3-heterophospholes (which include 1,3-diphospholes, by far the most studied) and 1,3-heteroarsoles, specifically 1,3-azaphospholes 1 and 5, 1,3-oxaphosphole 2, 1,3-thia-phosphole 3, 1,3-selenaphosphole 4, 1,3-diphosphole 6, the 1,3-diphospholyl anion 7, 1,3-azarsoles 8 and 12, 1,3-thiarsole 9, 1,3-selenarsole 10, and 1,3-phospharsoles 11 and 13. 

On protonation of the mixture of diphospholyl anion 28 and triphospholyl anion 54 generated by Na/Hg-treatment of /-BuC=P, a spontaneous Diels-Alder reaction occurred between the two systems and the tricyclic compound 55 was formed, the structure of which was determined by X-ray crystallography (Scheme 4) <1997JOM(536)273>. 

When 107 (R =/-Bu) was reacted with the gallium heterocycle 112, the diphospholyl anion 109 (R = /-Bu) was produced directly (Scheme 21) <2004JGD1971>. 

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