title: Cleavage of phosphorus-carbon (P-C) bonds of α-amino phosphonates with intramolecular hydrogen migration in the gas phase using electrospray ionization tandem mass spectrometry.
abstract: BACKGROUND
  α-Amino phosphonates with intrinsic biological activities have been used in a wide variety of applications. Because of the widespread existence of natural organophosphorus compounds containing P-C bonds such as the α-amino phosphonates, it is important to investigate the gas-phase chemistry of P-C bonds in order to determine their basic properties, which might provide some insights into their biosynthesis and catalytic cleavage.
  
  
  METHODS
  Twenty α-amino phosphonates were successfully synthesized and their fragmentation behavior was systematically investigated using in-solution deuterium labeling in combination with high-resolution Fourier transform ion cyclotron resonance (FTICR) electrospray ionization tandem mass spectrometry.
  
  
  RESULTS
  The fragmentation pathways of twenty α-amino phosphonates with different chemical structures were systematically studied. In general, P-C bonds could be easily cleaved via a novel intramolecular hydrogen atom migration from the amino group to the phosphoryl group through a five-membered-ring intermediate in the gas phase. A possible mechanism of the rearrangement of α-amino phosphonates is proposed.
  
  
  CONCLUSIONS
  An interesting intramolecular hydrogen atom migration between the amino and phosphoryl groups was observed with cleavage of the P-C bond in the molecule through a five-membered-ring intermediate. This characteristic fragmentation pathway not only provides some insights into the basic chemistry of compounds with P-C bonds, but could also have some applications in the structural determination of the α-amino phosphonate analogues.
authors.affiliation: Department of Chemistry and The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
authors.forename: Yuzhen
authors.initials: Y
authors.lastname: Gao
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Yaohui
authors.initials: Y
authors.lastname: He
authors.forename: Guo
authors.initials: G
authors.lastname: Tang
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Lin
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Yufen
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D008970:Molecular Weight; D063065:Organophosphonates / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D005740:Gases; D063065:Organophosphonates; D010758:Phosphorus; D002244:Carbon; D006859:Hydrogen