The reaction in air between nitromethane and BF3?OEt2 in the presence of ethylene gives isoxazole which has been trapped by platinum(II) through reaction with (Ph3-PCH2Ph)2[PtCl4] to produce the isoxazole complex (Ph3-PCH2Ph)[PtCl3(C3H 3NO)] which has been characterized spectroscopically, crystallographically and by independent synthesis.