Synthesis, Structure, and Chemical Properties of 1,3,2-Benzoxazaphospholenes

• Published in: Russian journal of general chemistry 2023-12, Vol.93 (Suppl 3), p.S688-S702
• Main Authors: Klimashevskaya, A. V., Arsenyeva, K. V., Cherkasov, A. V., Yakushev, I. A., Piskunov, A. V.
• Format: Article
• Language: English
• Subjects: Adducts; Aminophenol; Benzoquinone; Chemical properties; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Lewis acid; Nickel carbonyl; Olefins; Oxidizing agents; Ring opening
• ISSN: 1070-3632; 1608-3350
• DOI: 10.1134/S1070363223160065

O , N -Heterocyclic phospholenes ( t Bu Ap)PCl, ( Ph Ap)PCl, ( Ph Ap)PPh and ( Phenox Ap)PCl based on sterically hindered 4,6-di- tert -butyl-N-(R)- о -aminophenols ( R Ap, R = t Bu, Ph) and 2,4,6,8-tetra- tert -butyl-1 H -phenoxazin-1-one ( Phenox Ap) were synthesized and structurally characterized. The diverse reactivity of the synthesized compounds towards reducing, oxidizing agents and Lewis acids was observed. Reduction of ( t Bu Ap)PCl leads to a dimeric diphosphole. The oxidative addition of 3,6-di- tert -butyl -o- benzoquinone and 4,6-di- tert -butyl- N -(2,6-di-isopropyl-phenyl) -o- iminoquinone to the phosphorus in ( Ph Ap)PCl gives new pentacoordinated P V compounds containing two different dianionic redox-active ligands. Bis -o- amidophenolate ( Phenox Ap) 2 PBr was prepared by the reaction of 2,4,6,8-tetra- tert -butyl-1 H -phenoxazin-1-one with PBr 3 and cyclohexene. Dissolution of ( Phenox Ap) 2 PBr in THF promotes the ring opening reaction of the cyclic ether. The reaction of ( Ph Ap)PCl with Ni(CO) 4 and Fe 2 (CO) 9 leads to the stable P III adducts ( Ph Ap)P(Cl)–Ni(CO) 3 and ( Ph Ap)P(Cl)–Fe(CO) 4 .