31277-98-2Relevant articles and documents
Chiral platinum duphos terminal phosphido complexes: Synthesis, structure, phosphido transfer, and ligand behavior
Scriban, Corina,Glueck, David S.,DiPasquale, Antonio G.,Rheingold, Arnold L.
, p. 5435 - 5448 (2006)
Treatment of Pt halide precursors with the secondary phosphine PHMe(Is) in the presence of the base NaOSiMe3 gave the terminal phosphido complexes Pt(Duphos)(Ph)(PMeIs) (Is = 2,4,6-(i-Pr)3C 6H2, Duphos = (R,R)-Me-Duphos (1), (R,R)-i-Pr-Duphos (2)), Pt((R,R)-Me-Duphos)(X)(PMeIs) (X = I (3), Cl (4)), and Pt((R,R)-Me-Duphos) (PMeIs)2 (5). Low-barrier pyramidal inversion in the phosphido complexes was investigated by 31P NMR spectroscopy. Protonation of 1-5 with HBF4 gave the secondary phosphine complexes [Pt(Duphos)(Ph)(PHMeIs)][BF4] (Duphos = (R,R)-Me-Duphos (6), (R,R)-i-Pr-Duphos) (7)), [Pt((R,R)-Me-Duphos)(X)(PHMeIs)][BF4] (X = I (8), Cl (9)), and [Pt((fl,/?)-Me-Duphos)(PHMeIs)2][BF 4]2 (10); cations 6, 9, and 10 were prepared independently from Pt chloride precursors using Ag(I) salts and PHMe(Is) and then deprotonated to yield phosphido complexes 1-5. Oxidation of the phosphido ligands in 4 and 5 with H2O2 gave Pt((R,R)-Me-Duphos)(Cl) (P(O)MeIs) (11) and Pt((R,R)-Me-Duphos)(P(O)-MeIs)2 (12), respectively. Complexes 1-6, 9, and 11 were structurally characterized by X-ray crystallography; structural and 31P NMR results suggest the trans influence order P(O)MeIs > PMeIs > PHMe(Is). Reaction of 1 with [Pd(allyl)Cl]2, followed by treatment with dppe, gave Pt((R,R)-Me-Duphos)-(Ph)(Cl), PMeIs(allyl) (13), and Pd(dppe)2. Treatment of 1 with Pd(P(o-Tol)3)2 gave an equilibrium mixture containing the two-coordinate palladium complex Pd(P(o-Tol) 3)(μ-PMeIs)Pt((R,R)-Me-Duphos)(Ph) (14), Pd(P(o-Tol) 3)2, P(o-Tol)3, and 1.
Transition metal chemistry of low valent group 13 organyls
Gemel, Christian,Steinke, Tobias,Cokoja, Mirza,Kempter, Andreas,Fischer, Roland A.
, p. 4161 - 4176 (2007/10/03)
The coordination of low-valent group 13 organyls EIR [E = Al, Ga, In; R = Cp*, C(SiMe3)3] to transition metals has attracted increasing interest over the past decade. Complexes and cluster compounds of these new ligands with a number of transition metals have been isolated and characterised. The EIR moiety is formally isolobal with CO and PR3 (R = alkyl, Cp*) or carbenes (R = chelating group) with varying σ-donor and π-acceptor properties depending on the organic group R as well as the group 13 metal E. In this review, different ways of forming M-E bonds such as substitution reactions of labile ligands or insertion of EIR into transition metal halide bonds are described. Furthermore, the reactivity of homoleptic complexes Ma(EIR) b, is discussed, outlining the use of these new complex types in bond activation reactions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Palladium-catalyzed asymmetric phosphination. Enantioselective synthesis of PAMP-BH3, ligand effects on catalysis, and direct observation of the stereochemistry of transmetalation and reductive elimination
Moncarz, Julian R.,Brunker, Tim J.,Jewett, John C.,Orchowski, Michael,Glueck, David S.,Sommer, Roger D.,Lam, Kin-Chung,Incarvito, Christopher D.,Concolino, Thomas E.,Ceccarelli, Christopher,Zakharov, Lev N.,Rheingold, Arnold L.
, p. 3205 - 3221 (2008/10/08)
The complexes Pd(diphos)(o-An)(I) (o-An = o-MeOC6H4; diphos = dppe (3), (S,S)-Chiraphos (4), (R,R)-Me-Duphos (5), (R,S) -t-Bu-Josiphos (6), (R)-Tol-Binap (7)) were prepared. Complex 6 catalyzed the coupling of PH(Me)(Ph)(BH3) (2) with o-AnI in the presence of base to yield PAMP-BH3 (P(Me)(Ph)(o-An)(BH3) (1)) in low enantiomeric excess. The course of stoichiometric reactions of 3-7 with 2 and NaOSiMe3 depended on the diphosphine ligand. Complexes 6 and 7 gave PAMP-BH3 (1) and Pd(0) species; no intermediates were observed. With 3, the intermediate Pd(dppe)(o-An)(P(Me)(Ph)(BH3)) (10) was observed by 31P NMR, while 4 gave the isolable diastereomeric palladium complexes (Sp)-Pd((S,S)-Chiraphos)(o-An)(P(Me)(Ph)(BH3)) (11a) and (RP)-Pd((S,S)-Chiraphos)(o-An)(P(Me)(Ph)(BH3)) (11b), whose absolute configurations were determined by X-ray crystallography after separation. The analogous Pd((R,R)-Me-Duphos)(o-An)(P(Me)(Ph)(BH3)) diastereomers (12a,b) were also separated and isolated. Treatment of 4 with highly enantioenriched 2 (R or S) gave 11a or 11b in high diastereomeric excess with retention of configuration at phosphorus. P-C reductive elimination from either isomer of highly diastereoenriched 11 in the presence of excess diphenylacetylene yielded Pd((S,S)-Chiraphos)(PhC≡CPh) (14) and highly enantioenriched PAMP-BH3 (1), with retention of configuration.
