106584-00-3Relevant academic research and scientific papers
Palladium-assisted macrocyclization approach to cytochalasins: A synthesis of antibiotic A26771B
Trost,Brickner
, p. 568 - 575 (1983)
A synthetic strategy to macrocycles possessing a gamma -oxo delta -hydroxy-, gamma , delta -dihydroxy- and gamma -hydroxy- alpha , beta -unsaturated carbonyl system derives from a palladium-catalyzed C-C bond-forming reaction. In this approach, the macrocyclization employs a beta -keto sulfone as an electrofugal group and a 2-ethoxyallyl acetate as a nucleofugal group mediated by a phosphine-palladium (0) complex. In addition to facilitating anion formation and nucleophilic attack on the ( pi -allyl) palladium intermediate, the benzenesulfonyl group serves as a stereochemical control element which permits relay of stereochemical information between remote centers. The total synthesis of antibiotic A26771B is completed in 12 steps from 10-undecenal to illustrate the applicability of this methodology. Refs.
Fluoride-induced reduction of palladium(II) and platinum(II) phosphine complexes
Mason,Verkade
, p. 2212 - 2220 (2008/10/08)
A novel redox reaction involving fluoride and phosphine complexes of palladium(II) is reported. The scope of this reaction has been investigated using the ligands PPh3, Ph2P(CH2)nPPh2 (n = 1-4), Ph2PCH2C(CH3)2CH2PPh 2, Ph2PCH3, and P(CH2CH2CN)3; several solvents including DMSO, pyridine, acetonitrile, and THF; and either n-Bu4NF·3H2O or KF/18-crown-6 as the fluoride source. The reduction products are palladium(0) phosphine complexes for which this reaction offers a convenient synthetic route. 31P and 19F NMR spectra permitted identification of the initial oxidation products as difluorophosphoranes (R3PF2), which subsequently hydrolyzed, forming phosphine oxides if a hydrated fluoride source is used. Results implicating a fluoride-induced redox reaction in the thermal decomposition of [(Ph3P)3PdCl]BF4 to yield [Pd3Cl(PPh2)2(PPh3) 3]BF4 are also presented. Preliminary results indicate that platinum complexes also undergo this reaction, but nickel complexes yield NiF2. The X-ray parameters for Pd(dppp)2 (dppp = 1,3-bis(diphenyphosphino)propane) are: monoclinic, space group C2/c (No. 15), a = 18.396 (2) A?, b = 13.290 (1) A?, c = 20.186 (2) A?, β = 109.383 (5)°, and Z = 4.
