281199-46-0Relevant articles and documents
Regio- and enantioselective catalytic hydrophosphorylation of vinylarenes
Shulyupin, Mstislav O.,Francio, Giancarlo,Beletskaya, Irina P.,Leitner, Walter
, p. 667 - 672 (2005)
Regioselective and stereoselective hydrophosphorylation of vinylarenes 1 with pinacol H-phosphonate 2 can be achieved with transition metal catalysts. The use of rhodium catalysts such as the Wilkinson complex leads to the anti-Markovnikov adducts 3 as the only observable reaction products. In contrast, palladium catalysts give high selectivities for the Markovnikov adducts 4. In the presence of (R,S)-BINAPHOS as a chiral ligand, significant enantioselectivities have been obtained for the first time in hydrophosphorylation reactions.
A new class of 3′-sulfonyl binaphos ligands: Modulation of activity and selectivity in asymmetric palladium-catalysed hydrophosphorylation of styrene
Barta, Katalin,Francio, Giancarlo,Leitner, Walter,Lloyd-Jones, Guy C.,Shepperson, Ian R.
scheme or table, p. 2013 - 2023 (2009/08/14)
Palladium-catalysed monophosphorylation of (R)-2,2′- bisperfluoroalkanesulfonates of BINOL (RF = CF3 or C 4F9) by a diaryl phosphinate [Ar2P(O)H] followed by phosphine oxide reduction (Cl3SiH) then lithium diisopropylamide-mediated anionic thia-Fries rearrangement furnishes enantiomerically-pure (R)-2′-diarylphosphino-2′-hydroxy-3′- perfluoralkanesulfonyl-1,1′-binaphthalenes [(R)-8ab and (R)-8g-j], which can be further diversified by Grignard reagent (RMgX)-mediated CF 3-displacement [→(R)-8c-f]. Coupling of (R)-8a-j with (S)-1,1′-binaphthalene-2,2′-dioxychlorophosphine (S)-9 generates 3′-sulfonyl BINAPHOS ligands (R,S)-10a-j in good yields (43-82%). These new ligands are of utlility in the asymmetric hydrophosphonylation of styrene (1) by 4,4,5,5-tetramethyl-1,3,2-dioxaphospholane 2-oxide (2), for which a combination of the chiral ligands with either [Pd(Cp)(allyl)] or [Pd(allyl)(MeCN)2]+/NaCH(CO2Me)2 proves to be a convenient and active pre-catalyst system. A combination of an electron-rich phosphine moiety and an electron-deficient 3′-sulfone moiety provides the best enantioselectivity to date for this process, affording the branched 2-phenethenephosphonate, (-)-iso-3, in upto 74% ee with ligand (R,S)-10i, where Ar=p-anisyl and the 3′-SO2R groupis triflone.
