A study on the ability of 2,5‐dihydro‐ and 2,3,4,5‐tetrahydro‐1h‐phosphole oxides, as well as 7‐phosphanorbornene 7‐oxide derivatives to undergo uv light‐mediated fragmentation‐related phosphinylation of methanol

Reactivity of the title P‐heterocycles ( 1‐14 ) in the photoinduced fragmentation‐related phosphinylation of methanol was found to be influenced by the extent of ring strain and the UV absorption at 254 nm. The 7‐phosphanorbornene oxides ( 7‐14 ) are universal precursors due to their ring strain, no matter if they are UV‐active or not at 254 nm. The easily available 2,5‐dihydro‐1 H ‐phosphole oxides can be applied only in case of 1‐phenyl substitution that enhances the absorption at 254 nm. The ring strain of representative P‐heterocycles ( 5‐8 ) was evaluated by HF/6‐31G* and B3LYP/6‐31+G* calculations. UV spectra of compounds 5‐8 were interpreted by ZINDO/S and MNDO‐d calculations. The new precursors ( 11‐14 ) made possible the extension of the phosphinylations.