Publication Type
Peer Reviewed Journal
Mandatory Citation Fields
Niall P. Kenny, Dr. Kamalraj V. Rajendran, Elizabeth V. Jennings, Prof. Declan G. Gilheany*
2013
September
Chemistry - A European Journal
Cleavage of P=O in the Presence of P¿N: Aminophosphine Oxide Reduction with In Situ Boronation of the PIII Product
Published
Optional Fields
Please enter separate search keywords on separate lines
aminophosphine oxide;chemoselectivity;in situ protection;main group elements;reduction
19
42
14210
14214
In contrast to tertiary phosphine oxides, the deoxygenation of aminophosphine oxides is effectively impossible due to the need to break the immensely strong and inert P"[DOUBLEO bond in the presence of a relatively weak and more reactive P"[BOND]"N bond. This long-standing problem in organophosphorus synthesis is solved by use of oxalyl chloride, which chemoselectively cleaves the P"[DOUBLEO bond forming a chlorophosphonium salt, leaving the P"[BOND]"N bond(s) intact. Subsequent reduction of the chlorophosphonium salt with sodium borohydride forms the PIII aminophosphine borane adduct. This simple one-pot procedure was applied with good yields for a wide range of P"[BOND]"N-containing phosphoryl compounds. The borane product can be easily deprotected to produce the free PIII aminophosphine. Along with no observed P"[BOND]"N bond cleavage, the use of sodium borohydride also permits the presence of ester functional groups in the substrate. The availability of this methodology opens up previously unavailable synthetic options in organophosphorus chemistry, two of which are exemplified.
10.1002/chem.201302907
Grant Details
  • © University College Dublin 2010
  • Privacy
  • Policy
  • Freedom of Information