| Abstract
| - Several substituted cyclopentadienyl anions react with FeCl2 to afford a novel class of multidentate ferrocenyl polyphosphines; the proposed synthetic method represents a unique means to produce achiral dissymmetric 1,1‘,2-substituted ferrocenes bearing a 1‘-substituent different from the homoannular 1- and 2-substituents. Several new metalloligands exhibit intriguing conformational properties and rare “through-space” phosphorus nuclear-spin couplings.
- Several monosubstituted-cyclopentadienyl anions (A-Li) and [1,2-bis(diphenylphosphino)-4-tert-butylcyclopentadienyl]lithium (B-Li) react with FeCl2 to afford a novel class of multidentate ferrocenylphosphines (A-Fe-B). The proposed synthetic method represents a unique means to produce achiraldissymmetric 1,1‘,2-substituted ferrocenes (A-Fe-B) bearing a heteroannular 1‘-substituent which is differentfrom the homoannular 1- and 2-substituents. The selectivity for the two-step reaction favors formationof the desired dissymmetric product (A-Fe-B) rather than the concurrent formation of the symmetric di-and tetrasubstituted ferrocenes (A-Fe-A and B-Fe-B). Therefore, this method allows access to a greatnumber of dissymmetric multidentate metalloligands, especially when one considers that functionalized-Cp salts continue to expand in terms of number and diversity. Herein, emphasis was placed upon the 1H,13C, and 31P NMR characterization of the metalloligands; several examples exhibit intriguing conformationalproperties and rare “through-space” phosphorus nuclear-spin couplings.
|
