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

Abstract

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‐1H‐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.

A new P‐heterocyclic family: A variety of six‐membered and bridged P‐heterocycles with 1‐benzyl substituent

“…Photolyses were conducted in a photochemical reactor equipped with a quartz, water-cooled immersion well with a high-pressure mercury lamp (125 W). The starting 1-benzyl-3-SCHEME 6 SCHEME 7 methyl-2,5-dihydro-1H-phosphole oxide (1) was prepared as described earlier [15].…”

Synthesis of Phosphinic Acid Derivatives; Traditional Versus up-to-Date Synthetic Procedures

“…However, 5-or 6-membered P-heterocycles, such as phospholene oxides, could also be used [82,83]. The reactive phosphinidenes could also be generated thermally from strained cyclic phosphine oxides, such as phosphanorbornenes [84].…”