Syntheses and Reactions of Rhenium Carbamoyl Complexes of the Type (CO) 4 Re(NH 2 R)(CONHR) (R = Ethyl, Allyl or Isopropyl)

Carbamoyl complexes, (CO) 4 Re(NH 2 R)(CONHR)(R = ethyl, 1; R = allyl, 2; R = isopropyl, 3) were prepared by reactions of (CO) 5 ReBr (or (CO) 5 ReCH 2 SiMe 3 ) with appropriate amines. Complexes 1, 2 and 3 reacted with CH 3 CH 2 COCl to give Re(CO) 5 (NH 2 R) + Cl − (R = ethyl, 4; R = allyl, 5; R ‐ isopropyl, 6). Complex 5 undergoes nucleophilic attack by KOMe to give the alkoxycarbonyl complexes (CO) 4 Re(NH 2 ‐Allyl)(COOMe), 7. Complexes 4, 5, 6 and 7 were transformed to the corresponding carbamoyl complexes by reacting with appropriate amines. The reactions between the carbamoyl complexes and R″OH/CHCl 3 in air at room temperature gave the proposed products [(CO) 4 Re(NH 2 R)] 2 O (R = allyl, 8; R = isopropyl, 9), respectively. Complex 8 can also be prepared by heating 7 in CDCl 3 at 63–68°C for several days. The structure of 1 was confirmed by a X‐ray crystallographic study. Crystallographic data: space group P2 1 /c, a = 8.193 (3) Å, b = 19.273 (3) Å, c = 9.348 (8) Å, β = 110.37 (4)°, V = 1383.68 Å 3 , Z = 4; R(F) = 0.027, R w (F) = 0.030, based on 1888 reflections with I > 2.5σ(I). The other complexes were characterized by 1 H NMR, 13 CNMR, IR and mass spectra.