Chemistry of metallacyclic alkenylcarbene complexes V. Synthesis, structure and SN2′-type reactions of a chelated iron (η2-olefin) dioxocarbene complex
摘要:
The novel ferracyclic (eta(2)-alkene)carbene complexes of type 3 and 9 are easily accessible either from the corresponding (omega-alkenyl)carbene complexes 1 or from the chelated (eta(2)-olefin)acyl complex 8, depending on the central metal fragment and the heteroatom substituent X at the carbene carbon atom. X-ray structural data of 9 are provided and compared with those of 3 and similar metallacycles of the 'earlier' transition metals W and Mn. With nucleophiles, 9 yields new (eta(2)-olefin) complexes bearing a substituted rearranged alkene ligand in an S(N)2'-type reaction, thus offering a new method for the a-allylation of carbon nucleophiles like enoxyborates.