1384754-34-0Relevant academic research and scientific papers
α-Phosphanyl amino acids: Synthesis, structure and properties of alkyl and heterocyclic N-substituted diphenylphosphanylglycines Dedicated to Professor Dr. Dr. h.c. Manfred Scheer on the occasion of his 60th birthday
Lach, Joanna,Peulecke, Normen,Kindermann, Markus K.,Palm, Gottfried J.,K?ckerling, Martin,Heinicke, Joachim W.
, p. 4933 - 4945 (2015/06/23)
N-Alkyl and N-heterocyclic substituted diphenylphosphanylglycines 1a-j were synthesized by a convenient one-pot, three-component reaction of diphenylphosphane, the corresponding primary amine and glyoxylic acid hydrate in diethyl ether. Phosphanylglycolates 2 and phosphoniobis(glycolates) 3 were detected as intermediates. In the case of steric hindrance or low basicity of the amine only 2 or mixtures of 2 and 1 are formed. Reactivity studies of selected phosphanylglycines showed facile decarboxylation and hydrolysis, oxidation and formation of coordination compounds with BH3 or W(CO)5. N-Alkyl derivatives (tert-butyl, n-hexyl, benzhydryl) with moderate steric hindrance reacted with Ni(COD)2 in THF or toluene in the presence of ethylene with heating under pressure to yield highly active oligomerization catalysts, and converting the ethylene to liquid and low-molecular-weight solid ethylene oligomers (MNMR 500-1250 g/mol) with high selectivity for linear α-olefins. Smaller N-alkyl or N-heterocyclic amino substituents at the phosphanyl acetic skeleton interfere with the ethylene conversion and deactivate the catalyst. The structures of the compounds were elucidated by solution NMR and single crystal XRD studies.
Phosphonium bis(glycolates) and phosphinoglycolates: Synthesis, solvolysis, oxidation to (thio)phosphinoylglycolates and use as ligands in Ni-catalyzed ethylene oligomerization
Peulecke, Normen,Kindermann, Markus K.,K?ckerling, Martin,Heinicke, Joachim
experimental part, p. 61 - 69 (2012/08/27)
Secondary phosphines, glyoxylic acid hydrate and amines react to form organoammonium phosphonium bis(glycolates) 1a-d. In CD3OD solution, diphenylphosphonium bis(glycolates) undergo reversible solvolysis to phosphinoglycolates 2a,b and acetalic glyoxylic species. The P-dialkyl species 1c avoids this and maintains the phosphonium bis(glycolate) structure in CD 3OD (cHex2P) or undergoes further solvolysis with partial formation of R2PH (R = tBu). Condensation to phosphinoglycines, e.g. 3b, observed for primary amines, does not take place with N-secondary amines at room temperature. Heating leads to condensation but is followed by decarboxylation as shown for the conversion of 2a to 4a. Because of the kinetic lability, the phosphonium compounds 1a-d are sensitive to oxidation by air, H2O2, or sulfur. The resulting phosphinoyl and thiophosphinoyl glycolates and glycolic acids 5-8 are kinetically stable. Precatalyst solutions formed from 1a, c, d and Ni(COD)2 in THF developed moderate to good activity in the oligo- or polymerization of ethylene to linear products containing methyl and vinyl end groups. Activity and molecular weights increased with the +I-effect of the P-substitutents. The solution structures of the novel compounds were elucidated by multinuclear NMR spectroscopy. For 7a a crystal structure analysis is also presented.
