Formation of Fischer-Type Aminocarbenes by a Double C−H Bond Activation of a Methylamino Group^⊥

The reaction at room temperature of [RuCl2(PPh3)3] and the ferrocenyl aminophosphine ligand PAPF leads to the product [RuCl2(PPh3)(PAPF)], 1c, in equilibrium with the starting materials. A shift of the reaction toward the formation of 1c was observed with temperature. At 130 °C, 1c was transformed into the chelate aminocarbene complex [RuCl2(PPh3)(PAPF-c)], 2, after a double C−H activation of the aminomethyl fragment. Complex 2 exhibits in the solid state a strong agostic interaction (X-ray structure determination) that is also maintained in solution. An intermediate of the transformation of 1 into 2 has been observed in solution. When complex 2 is heated in DMSO, displacement of the PPh3 ligand by DMSO takes place, while the agostic interaction remains unchanged. The similar complexes [RuCl2(PPh3)(PN)], with the ligand PPFA or PTFA, did not undergo any transformation upon heating and the aminocarbene group was not formed.