alpha-Phosphanyl Amino Acids: Synthesis, Structure and Reactivity of N-Aryl-alpha-phosphanylglycines

作者:Lach Joanna; Guo Cun Yue; Kindermann Markus K; Jones Peter G; Heinicke Joachim*
来源:European Journal of Organic Chemistry, 2010, (6): 1176-1186.
DOI:10.1002/ejoc.200901251

摘要

The novel N-aryl-alpha-phosphanylglycines la-d have been easily prepared by one-pot three - component reactions of diphenylphosphane, primary arylarnines and glyoxylic acid flydrate in diethyl ether. The reactions proceed via intermediate arylammonium (diphenylphosphanyl)glycolates 2 and stop at this stage in the case of N-secondary anilines, for example, the stable N-methylaniliniurn phosphanylglycolate 3. The conversion of 2 into I is an equilibrium, as demonstrated by the reversible hydrolysis of Ib to 2b in [D(8)]THF containing varying amounts of water. The solid ct-phosphanyl amino acids are stable, but in THF or DMSO solution they suffer from slow decarboxylation, which becomes rapid on heating at about 80 degrees C, yielding N-seconclary phosphanylmethylanitines 4. Solutions of 1 in the polar protic solvent methanol are stable over long periods, but show rapid proton/deutermin exchange even of the alpha-CH proton in deuteriornethanol and thus increased CH acidity compared with normal a-arnino acids, This and the sensitivity to hydrolysis hint at an acetallike character and partial protonation even at the phosphorus atom. Oxidation of the N-aryl derivatives 1b,c by aqueous H(2)O(2) proceeds more rapidly than hydrolysis and provides the first examples of phosphinoylglycines 5. Oxidation by sulfur is rapid even at room temperature in methanol, giving the thiophosphinoylglycines 6. The coordination properties of 1 at the phosphanyl group are characterized by the reaction of lb with [M(VI)(CO)(5)(THF)] (M(VI) = Cr, Mo, W) and the coordination chemical shifts in the NMR spectra and shifts in the IR spectra of the resulting [(Ib)M(VI)(CO)(5)] complexes 7b-9b. The structures of the new compounds were elucidated by crystal structure analysis of Ib and 6b and the solution NMR spectroscopic data of all the compounds. Screening for the nickel-catalysed oligomerization of ethylene showed the formation of active catalysts from I and Ni(cod)(2).

  • 出版日期2010-2