Synthesis and Structure of P,N-Heterodifunctional Ferrocene Ligands and their Transition Metal Complexes for Palladium-Catalyzed Aryl Amination Reaction

Iminophosphorane–phosphines: Versatile ligands for homogeneous catalysis

“…Thus, while the use of trimethylsilylacetylene was inefficient due to the significant desilylation of the product that takes place under the reaction conditions to give symmetrically disubstituted alkynes, the use of triisopropylsilylacetylene gave rise to the desired mono-aryl-substituted alkynes in excellent yields (Scheme 9) [37]. The ability of complex 32 to promote aryl-amination C-N couplings has also been briefly described using 4-iodotoluene and N-benzylmethylamine as model substrates (Scheme 10) [38]. The best result was obtained when a mixture of 4-iodotoluene (1 equiv.…”

Ferrocensubstituierte 1,3-bidentate Liganden und ihre heteronuklearen Übergangsmetallchelate

“…Ferrocenhaltige Liganden für Übergangsmetallionen, bei welchen das zweitgenannte Baumotiv verwirklicht ist, finden sich nur selten in der Literatur [26] und das, obwohl in vielen Beispielen bei Koordination von Übergangsmetallionen an Rezeptoren gesättigter Cp-Seitenketten keine oder nur äußerst geringe Beeinflussungen des Fc/Fc + -Potentials beobachtet werden konnten [14b, 15a, 27].…”

Synthesis of Calixarene‐Based Bis(iminophosphoranes) and Their Use in Suzuki–Miyaura Cross‐Coupling

“…[9][10][11][12][13][14][15][16] This is mainly due to the nature of the P=N bond, which involves a zwitterionic contribution, thus making stabilisation of coordinated metal atoms in low oxidation states difficult. [19][20][21][22][23][24][25][26] We have recently described conical calix [4]arenes in which two distal phosphanyl groups are attached at the upper rim of the macrocycle and have shown that such phosphanes, when associated with palladium, could function as efficient cross-coupling catalysts. [19][20][21][22][23][24][25][26] We have recently described conical calix [4]arenes in which two distal phosphanyl groups are attached at the upper rim of the macrocycle and have shown that such phosphanes, when associated with palladium, could function as efficient cross-coupling catalysts.…”

“…[17,18] However, recent studies have shown that functionalised iminophosphoranes capable of forming chelate complexes can be used both in carbon-carbon and carbon-heteroatom bond formation. [19][20][21][22][23][24][25][26] We have recently described conical calix [4]arenes in which two distal phosphanyl groups are attached at the upper rim of the macrocycle and have shown that such phosphanes, when associated with palladium, could function as efficient cross-coupling catalysts. [27,28] The good performances of the catalysts were shown to be related to the size and structural properties of the calixarene backbone.…”