Organphosphorus Compounds, Part 150; Imidovanadium(V)-Complexes as Reaction Partners for Kinetically Stabilized Phosphaalkynes. 1-Aza-2-phospha-4-vanada(V)-cyclobutenes: Precursors in the Synthesis of 1H-1,2-Azaphospholes
作者:Christoph Peters、Frank Tabellion、M. Schröder、U. Bergsträßer、Fritz Preuss、Manfred Regitz
DOI:10.1055/s-2000-6353
日期:——
A new synthetic pathway to the 1H-1,2-azaphospholes 12a-m has been developed involving reactions of the 1-aza-2-phospha-4-vanada(V)-cyclobutenes 9a-g, generated in situ from the imidovanadium(V) complexes 7a-c and the phosphaalkynes 8a-e, with the acetylenes 10a-g. This synthesis affords the heterocyclic compounds 12a-m in good yields and allows variation of all substituents for the first time. The structure of the 1H-1,2-azaphosphole 12a has been confirmed by X-ray crystallographic analysis. A selective η1-complexation of the azaphospholes 12a,b to afford the transition metal complexes 13a,b can be realized by reaction with diiron nonacarbonyl. While reactions of the alkyl trifluoromethanesulfonates 14a,b with the heterophosphole 12a result in the formation of the azaphospholium compounds 15a,b, the azaphosphole 12a reacts with the azo compound 16 to form the spirotricyclic betaine 17. Diels-Alder reactions occur when the heterophospholes 12a,b are treated with the electron-poor acetylenes 18a-e and furnish the 1,2-azaphosphanorbornadienes 19a-f, the structures of which have been confirmed by an X-ray crystallographic analysis of the bicyclic product 19e. The phosphorus atom of the azaphosphanorbornadiene 19a can be oxidized and sulfurized to form the bicyclic species 20 and 21 containing λ5Ï4-phosphorus atoms.
一种合成1H-1,2-氮杂膦杂螺12a-m的新型合成途径已被开发,涉及1-氮杂-2-膦-4-钒(V)-环丁烯9a-g与炔烃10a-g的反应,这些环丁烯是由咪唑钒(V)络合物7a-c和膦炔8a-e现场生成的。这种合成方法提供了高产率的杂环化合物12a-m,并且首次允许所有取代基的变化。1H-1,2-氮杂膦杂螺12a的结构通过X射线晶体学分析得到确认。通过与九羰基二铁反应,可以选择性地形成氮杂膦杂螺12a,b的η1-络合物,得到过渡金属络合物13a,b。当三氟甲磺酸烷基酯14a,b与杂膦杂螺12a反应时,会形成氮杂膦鎓化合物15a,b,而氮杂膦杂螺12a与偶氮化合物16反应会形成螺三环甜菜碱17。当杂膦杂螺12a,b与缺电子炔烃18a-e反应时,会发生Diels-Alder反应,生成1,2-氮杂膦杂诺环双烯19a-f,其结构通过双环产物19e的X射线晶体学分析得到确认。氮杂膦杂诺环双烯19a中的磷原子可以被氧化和硫化,形成含有λ5σ4-磷原子的双环物种20和21。