Straightforward access to multifunctional pi-conjugated P-heterocycles

We report the straightforward one-pot synthesis of 5 or 6-membered P-heterocycles featuring internal ylidic bond: P-containing acenaphthylenes and phenanthrenes. The stability of the compounds tolerates post-functionalization through direct arylation to introduce electron-rich/poor substituents and the synthetic strategy is also compatible with the preparation of more elaborated polyaromatic scaffolds such acenes and helicenes. Using a joint experimental and theoretical approach, we show that the molecular engineering of this platform allows not only tuning their absorption/emission on the entire visible range but also endowing them with chiroptical or non-linear optical properties, making them valuable dyes for a large panel of photonic or opto-electronic applications.