189197-86-2Relevant academic research and scientific papers
The difficulty of coordinating mutually trans phosphine and aryl ligands in palladium complexes and its relation to important coupling processes. Syntheses and crystal structures of a family of palladium phosphino, triflato, perchlorato, and aquo-2-(arylazo)aryl complexes
Vicente, José,Areas, Aurelia,Bautista, Delia,Jones, Peter G.
, p. 2127 - 2138 (2008/10/08)
The reaction between [Pd(C6H3N=NR-2, X-5)Cl]2 and phosphines gives [Pd(C6H3N=NTo-2,Me-5)Cl(L)] [To = C6H4Me-4, L = PEt3 (1a), PPh2Me (1b)] or trans-[Pd(C6H3N2To-2,Me-5)ClL2] (L = PEt3 (2a), PPh2Me (2b), L2 = bis(diphenylphosphino)methane = dppm (2c)) or trans-[Pd(C6H3N2X-2, R-5)Cl(μ-dppm)]2 (X = Me, R = To (3a); X - H, R = Ph (3b)), depending on the molar ratio of the reagents. Tl(QTf) (OTf = O3SCF3), AgClO4, or AgSbF6 react with 1a,b, 2a, 2c, or 3a to give, variously, [Pd(C6H3N=NTo-2,Me-5)(Y)(D] (L = PEt3, Y = TfO (4a); L = PPh2Me, Y = TfO (4b), ClO4 (4b′), trans-[Pd(C6H3N2To-2,Me-5)(OTf)(PEt 3)2] (5), [Pd(C6H3N2To-2,Me-5)(η 1-dppm)(η2-dppm)]Tfo (6), or [Pd(C6H3N=NR-2,X-5)(η2-dppm)]Y (X = Me, R = To, Y = TfO (7a)). Complexes [Pd(C6H3N=NR-2,X-5)(η2-dppm)]SbF 6 (X = Me, R = To (7a′); X = H, R = Ph (7b)) can be prepared by reacting [Pd(C6H3N=NR-2,X-5)Cl]2 with AgSbF6 and dppm. Complex 4b′ reacts with PPh2Me to give [Pd(C6H3N2To-2,Me-5)(PPh2Me) 3]ClO4 (8). Attempts to obtain single crystals of 4a, [Pd(C6H3N=NR-2,X-5)(PPh3)(Me 2CO)]ClO4, or 7b lead to different products. From 4, an insertion into the Pd-OTf bond of one molecule of water gives [Pd(C6H3N=NTo-2,Me-5(OH2-OTf)(PEt3)] (9) while substitution of the acetone molecule by two water molecules occurs in the second case to give [Pd(C6H3N=NTo-2,Me-5){(μ3-OH 2)(?OClO3)(OH2)}(PPh3)] (10). Finally, ready oxidation in the air of 7b gives [Pd(C6H4N=NPh-2)(η2-dppmO)]SbF6 (11) [dppmO = bis(diphenylphosphino)methane monoxide]. [Pt(PPh3)3] reacts with [Hg(C6H3N2To-2, Me-5)Cl] to give trans-tPt(C6H3N2To-2,Me-5)Cl(PPh 3)2] (12), which in turn reacts with Tl(OTf) to give [Pt(C6H3N=NTo2,Me-5)(PPh3)2]TfO (13). Crystal structures of 2c·-1/2CH2Cl2, 4b′, 5, 6, 7a, 9, 10, and 11·2MeOH have been determined.
