130611-73-3Relevant academic research and scientific papers
Thermal reactions of acyloxy and alkoxy carbene complexes with imines: Metathesis, acetate rearrangements, and a new route to imino carbene complexes via Peterson type eliminations
Murray, Christopher K.,Warner, Benjamin P.,Dragisich, Vera,Wulff, William D.,Rogers, Robin D.
, p. 3142 - 3151 (1990)
The first examples of the reactions of imines (R3N=CHR2; R3 = CH3, R2 = Ph, p-MePh) with acetoxy Fischer carbene complexes ((CO)5M=C(OAc)R1; M = Cr, W, R1 = Ph) are described. The reaction of the chromium complex gives exclusively the 0-acyl imidate 14 (MeN=C(OAc)Ph), which is the first example of a metathesis of an imine and a carbene complex. The tungsten complex gives a product that results from an unprecedented insertion of the imine into the carbene carbon-heteroatom bond along with the O-acyl imidate 14 as a minor product. This new insertion product was characterized by spectroscopic methods and by X-ray diffraction and determined to be the animal carbene complex 13b. Crystal data for 13b: space group P1, Z = 2, a = 8.269 (3) ?, b = 10.766 (5) ?, c = 13.851 (7) ?, α = 68.83 (5)°, β = 75.97 (6)°, γ = 81.39 (4)°, R = 0.046, and Rw = 0.050 for the 2267 reflections with Fo ≥ 5σ(Fo). It was determined that this insertion product is the result of an acetate transfer rather than a hydride transfer and that a likely intermediate in the mechanism is the zwitterion that results from initial addition of the imine nitrogen to the carbene carbon. The reaction of the acetoxy carbene complexes (CO)5M=C(OAc)R1 (M = Cr, W, R1 = Ph, Me, tBu) with N-trimethylsilyl imines Me3SiN=CHR2 provides a new method for the synthesis of imino carbene complexes (CO)5M=C(R1)N=CHR2 in a process that involves a Peterson type elimination. In a related reaction, it was found that imino complexes could also be accessed from the reaction of alkoxy carbene complexes (CO)5M=C(OMe)R1 (M = Cr, W, R1 = Ph, Me, tBu) with N-trimethylsilyl imines.
