- UV-mediated hydrophosphinylation of unactivated alkenes with phosphinates under batch and flow conditions
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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.
- Gelat, Fabien,Roger, Maxime,Penverne, Christophe,Mazzad, Ahmed,Rolando, Christian,Chausset-Boissarie, La?titia
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p. 8385 - 8392
(2018/03/09)
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- Rapid and Efficient Microwave-Assisted Hydrophosphinylation of Unactivated Alkenes with H -Phosphinic Acids without Added Metal or Radical Initiator
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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.
- Troupa, Panagiota,Katsiouleri, Georgia,Vassiliou, Stamatia
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supporting information
p. 2714 - 2719
(2015/11/27)
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- Recent advances in phosphorus-carbon bond formation: Synthesis of H-phosphinic acid derivatives from hypophosphorous compounds
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This account summarizes the research conducted in our laboratory over the past five years. New methodologies were devised for the formation of P-C bonds with a focus on the reactions of hypophosphorous acid derivatives. Three types of reactions have been developed: palladium-catalyzed cross-coupling, room-temperature radical addition, and palladium-catalyzed addition. Our results are summarized in each of these areas and include some of our most recent data. (1) Our palladium-catalyzed cross-coupling has been extended to the direct coupling of alkyl phosphinates with a variety of aryl, heteroaryl, and even alkenyl electrophiles. (2) The addition of sodium hypophosphite under radical conditions is extended from alkenes to alkynes. (3) The catalytic addition of hypophosphorous compounds using palladium catalysts (hydrophosphinylation) is also discussed.
- Montchamp, Jean-Luc
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p. 2388 - 2406
(2007/10/03)
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- Triethylborane-initiated room temperature radical addition of hypophosphites to olefins: Synthesis of monosubstituted phosphinic acids and esters
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A novel and practical approach to monosubstituted phosphinic acid (alkylphosphonous acid) derivatives from hypophosphite salts or esters is described. Phosphorus-centered radical formation is initiated with Et3B/O2, and the reaction is conveniently conducted at room temperature in an open flask. In contrast to previously reported conditions for the radical reaction of hypophosphorous acid and sodium hypophosphite (peroxide initiators, acid catalysis, heat), the method proceeds under neutral conditions and therefore tolerates a wide range of functional groups. Previously inaccessible phosphinic acids can be prepared in a single step from cheap starting materials. Excellent selectivity is observed for monoaddition, and symmetrical dialkyl phosphinates do not form in significant amounts. Monosubstituted phosphinic acids are usually obtained in better than 90% purity by a simple extractive workup; however, isolated yields are diminished if the substituent is polar. Because radicals derived from hypophosphites are electrophilic, the reaction is limited to the use of electron-rich olefins. The reaction conditions can also be employed in the room temperature radical reduction of alkyl halides and provide an exceptionally mild and environmentally friendly alternative to the use of tributyltin hydride. The remarkable mild nature of the reaction conditions allows for the radical reaction of sensitive alkyl hypophosphites to occur, in which case, a catalytic amount of Et3B suffices to deliver alkyl phosphinate esters in reasonable yield.
- Deprele,Montchamp
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p. 6745 - 6755
(2007/10/03)
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