UV-mediated hydrophosphinylation of unactivated alkenes with phosphinates under batch and flow conditions
A UV-mediated hydrophosphinylation of unactivated alkenes with H-phosphinates and hypophosphorous acid under radical free conditions is presented. The reaction affords selectively a large number of structurally diverse organophosphorous compounds in moderate to good yields under mild reaction conditions in the presence of an organic sensitizer as catalyst irradiated by UV-A LEDs. Furthermore, the high yielding hydrophosphinylation in continuous flow is disclosed.
Rapid and Efficient Microwave-Assisted Hydrophosphinylation of Unactivated Alkenes with H -Phosphinic Acids without Added Metal or Radical Initiator
A microwave-assisted hydrophosphinylation of unactivated alkenes with phosphinic acid and its derivatives under metal-free and initiator-free conditions is reported. Such hydrophosphinylations are operationally simple, use aqueous hypophosphorus acid, H-phenylphosphinic acid, and H-alkylphosphinic acids, and seem to proceed by a radical mechanism. Good isolated yields were obtained using a reasonable excess of the appropriate reagent.
Manganese-catalyzed and promoted reactions of H-phosphinate esters
H-Phosphinates react with alkenes and alkynes using catalytic manganese(II) acetate. Under stoichiometric conditions with manganese(III) acetate or with catalytic manganese(II) acetate+excess manganese(II) oxide various reactions like arylation or cyclization through radical oxidative arylation can take place. Whereas the chemistry of manganese is already well developed for the functionalization of H-phosphonates, the present methodology provides an unprecedented access to functionalized phosphinates in acceptable to good yields.
Fisher, Henry C.,Berger, Olivier,Gelat, Fabien,Montchamp, Jean-Luc
supporting information
p. 1199 - 1204
(2014/05/06)
Synthesis of disubstituted phosphinates via palladium-catalyzed hydrophosphinylation of H-phosphinic acids
The first metal-catalyzed hydrophosphinylation of unsaturated hydrocarbons with H-phosphinic acids is described. A strategy to activate the P-H bond through control of the tautomeric equilibrium using ethylene glycol is described. The reactions also avoid chromatographic purification. Copyright