Gao Y, Xu J, He Y, Tang G, Lin Z, Liu H, Gao X, Zhao Y. 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.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014;
28:1964-1970. [PMID:
25132296 DOI:
10.1002/rcm.6984]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/08/2014] [Accepted: 07/11/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE
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.
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