Features of 6-bromo-1,2-naphthoquinone reaction with 1,2-bis(diphenylphosphino)ethane

Dibromine Promoted Transmetalation of an Organomercurial by Fe(CO)5: Synthesis, Properties, and Cytotoxicity of Bis(2-C6H4-2′-py-κC,N)dicarbonyliron(II)

“…When complex 1 was reacted with 1,2-bis­(diphenylphosphino)­ethane (dppe) in CH 2 Cl 2 at 25 °C, 2 was formed in 18% yield together with a complex with an IR band at 1893 cm –1 (Figure S10). There are two doublets at 42.6 and −11.2 ppm with a J PP = 31.1 Hz in the 31 P­{ 1 H} NMR spectrum of the reaction mixture, which may be assigned to coordinated and free PPh 2 groups, respectively . Yields of 2 in the reactions of 1 with dppe and 1 eq of N∩N are similar (20 vs. 18%, respectively), suggesting that the nature of the entering ligand is not a crucial factor.…”

“…There are two doublets at 42.6 and −11.2 ppm with a J PP = 31.1 Hz in the 31 P{ 1 H} NMR spectrum of the reaction mixture, which may be assigned to coordinated and free PPh 2 groups, respectively. 54 Yields of 2 in the reactions of 1 with dppe and 1 eq of N∩N are similar (20 vs. 18%, respectively), suggesting that the nature of the entering ligand is not a crucial factor. Such behavior, that is, the promotion of the CO insertion into Fe II −C bonds by phosphines and other ligands, has been reported in the literature.…”

Reaction of 1,6-bis(diphenylphosphino)hexane with 6-bromo-1,2-naphthoquinone

“…Previously, we developed a new synthetic approach to phosphonium salts on the basis of the reaction of triphenylphosphine with 6-bromo-1,2-naphthoquinone I, in which the phosphorylation of naphthalene fragment occurs in the position 4 to form phosphorus ylide followed by its treating with hydrogen halides [7]. An attempt to extend this approach to 1,2-bis (diphenylphosphino)ethane led to the formation of phosphonium salts with only one phosphorus atom [8]. It may probably be due to steric hindrances to the double phosphorylation of the naphthalene ring.…”