Synthesis of alkyldibenzophosphole 5-oxides

Palladium-Catalyzed Synthesis of Dibenzophosphole Oxides via Intramolecular Dehydrogenative Cyclization

“…There are several methods to synthesize dibenzophospholes. , The most frequently used method is the reaction between 2,2′-dilithiated biaryls and PhPCl 2 followed by oxidation of the formed dibenzophospholes by air or H 2 O 2 . The following methods have also been reported: cyclization of 2-biphenylphenylphosphinic acids by intramolecular Friedel–Crafts reaction, treatment of triphenylphosphine oxide with 2 equiv of PhLi and successive oxidation of the formed dibenzophospholes, treatment of tetraphenylphosphonium bromide with lithium diethylamide followed by oxidation, thermolysis of m -terphenyldichlorophosphines, and Et 3 B- and O 2 -mediated radical cyclization of secondary phosphine oxides with a biphenyl group . Our new strategy for the synthesis of dibenzophosphole oxides is shown in Figure .…”

Synthesis of Dibenzophospholes by Tf2O-Mediated Intramolecular Phospha-Friedel–Crafts-Type Reaction

“…On the other hand, the intramolecular phospha-Friedel–Crafts reaction (PFC) is traditional but can be a good alternative to the aforementioned direct couplings. However, its synthetic potential has not been studied well: only a few examples were reported by using biarylphosphinic acid substrates and excess PCl 5 under harsh conditions (refluxed PhNO 2 solvent), and the regioselectivity in the reaction was also not mentioned . Thus, there still remains a large demand for development of the dibenzophosphole synthesis via intramolecular PFC reaction.…”

The Mechanism of Phosphonium Ylide Alcoholysis and Hydrolysis: Concerted Addition of the O−H Bond Across the P=C Bond

“…31 P NMR (121 MHz, [D 8 ]THF): δ =42.8 (0.04P, phosphine oxide EtDBPO, compound 26 , lit . δ P =46.11 ppm (CDCl 3 )), 33.2 (1P, phosphine oxide 27 , lit .…”