Bifunctionalized allenes. Part XXII. Coinage metal-catalyzed cycloisomerization of phosphorylated 3-(α- or β-hydroxyalkyl)allenes to 2-phosphoryl-2,5-dihydrofurans or 2-phosphoryl-5,6-dihydro-2H-pyrans

Synthesis of 2-phosphonoheterocycles via base-promoted 5-endo cyclization

“…[8] Another method to obtain phosphonodihydropyrroles was based on a metal-catalyzed cycloisomerization of (hydroxy)allenes (Scheme 1.c). [9] By examining the literature examples, no easy and general method has been reported. The starting material synthesis often required several steps whereas the scope of the reaction is relatively limited.…”