title: Acid-promoted transformations of 1-(diphenylphosphoryl)allenes: synthesis of novel 1,4-dihydrophosphinoline 1-oxides.
abstract: 1-(Diphenylphosphoryl)alka-1,2-dienes (phosphonoallenes) in Brønsted (super)acids (TfOH, FSO3H, and H2SO4) at -70 to 120 °C for 30 min to 4 h gave, at first, (3-hydroxyalk-1-en-1-yl)diphenylphosphine oxides, as kinetically favorable reaction products, that are further converted into 1-phenyl-1,4-dihydrophosphinoline 1-oxides as thermodynamically stable compounds. The latter compounds are formed from phosphonoallenes under the action of a strong Lewis acid AlCl3 at room temperature for 10-120 min. This is a novel, simple and efficient (short reaction time, high yields) method for synthesis of such 1,4-dihydrophosphinoline 1-oxides.
authors.affiliation: Department of Organic Chemistry, Institute of Chemistry, Saint Petersburg State University (SPbSU), Universitetsky pr., 26, Saint Petersburg, 198504, Russia.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Bogachenkov
authors.forename: Albina V
authors.initials: AV
authors.lastname: Dogadina
authors.forename: Vadim P
authors.initials: VP
authors.lastname: Boyarskiy
authors.forename: Aleksander V
authors.initials: AV
authors.lastname: Vasilyev