Phosphinoferrocene amides with glycine pendant groups

The reaction of 1′-(diphenylphosphino)-1-ferrocenecarboxylic acid (Hdpf) with H2NCH2CO2CR3 mediated by peptide coupling agents (EDC/HOBt) afforded novel glycine phosphino-carboxamides Ph2PfcCONHCH2CO2CR3 (fc = ferrocene-1,1′-diyl; R = H (2) and Me (3*)). Compound 2 was converted to its corresponding phosphine oxide (5*) and sulfide (6*), to N-acyl glycine Ph2PfcCONHCH2CO2H (7), and to bis-amide Ph2PfcCONHCH2CONH2 (8*). Compounds 2 and 8 reacted with [PdCl2(cod)] (cod = η2 :η2 - cycloocta-1,5-diene) and 7 reacted with Na2[PdCl4] to afford the respective, mostly solvated bis-phosphine complexes trans-[PdCl2(L-κP)2] (9: L = 2; 10: L = 7, 11: L = 8). Furthermore, bridge cleavage reaction of [{Pd(μ-Cl)(LNC )}2] (LNC = 2-[(dimethylamino-κN)methyl]phenyl- κC1 ) (12) with 2 gave [(LNC )Pd(Cl)(2-κP)] (13*), which was further reacted with AgClO4 or KOt-Bu to afford bis-chelate complexes [(LNC )Pd(2-κ2 O,P)]ClO4 (14*) and [(LNC )Pd(L- κ2 N,P)] (15*; L = 2 deprotonated at the NH group), respectively. All compounds were characterized by spectroscopic methods (multinuclear NMR, MS, and IR) and by elemental analyses; the asterisk indicates that the crystal structure has been determined. Phosphine 7 in combination with palladium(II) acetate were shown to be highly active catalysts for the Suzuki-Miyaura cross-coupling of..