320635-37-8

Upstream product

• 140224-25-5 Pt(C₆H₅)2PC₂₀H₁₂P(C₆H₅)2Cl₂ 
• 2923-28-6 silver trifluoromethanesulfonate 
• 425375-80-0 [(R-BINAP)Pt(S-BINOL)] 
• 1493-13-6 trifluorormethanesulfonic acid 

Downstream Products

• 425375-88-8 ((((C₆H₅)2PC₁₀H₆)2)Pt(C₅H₅))⁽¹⁺⁾*CF₃SO₃^(1-)=((((C₆H₅)2PC₁₀H₆)2)Pt(C₅H₅))(CF₃SO₃) 

Relevant academic research and scientific papers

Thermodynamic and kinetic relationships between Lewis acid-Lewis base complexes relevant to the P2Pt(OTf)2-catalyzed Diels-Alder reaction

The Pt(II) Lewis acids P2Pt(OTf)2 (2; P2 = dppe (a), R-BINAP (b)), which catalyze the Diels-Alder reaction of acryloyl-N-oxazolidinone (4) with cyclopentadiene (HCp), were generated in situ by activation of P2Pt(S-BINOL) precursors 1 with 2 equiv of triflic acid (HOTf). Catalysts 2 and catalytically relevant Lewis acid - Lewis base complexes [P2Pt(L2)]2+-[OTf]2- (L2 = 2 H2O (3), dienophile 4 (6), Diels-Alder adduct 5 (8)) were characterized by 1H and 31P NMR spectroscopy at 195 K. 2a was also characterized by X-ray crystallography. The thermodynamic relationships between 2, 3, 6, 8, and a BE4- analogue of 2 were determined through competitive binding experiments monitored by 31P NMR at 195 K, to assess the effects of competitive inhibition of counterions, additives, and product on substrate coordination to the catalyst. These experiments demonstrated that the Lewis bases bind to [P2Pt]2+ with relative strengths BF4- ? OTf- 2O. The rates of two ligand exchange processes (dienophile/dienophile (k1) and dienophile/OTf- (k2)) were measured at 270 K by simulation of exchange-broadened 31P NMR spectra of 2/6 equilibrium mixtures, revealing that ligand substitution occurs more rapidly in the dppe system than the R-BINAP system (180 times faster for k2). Finally, the reaction of HCp with 6 to give 8 was monitored by 31P and 1H NMR at 195 K; attack of HCp on Pt-coordinated 4 occurred much faster than ligand exchange, indicating that ligand exchange is the turnover-limiting step of the catalytic cycle.

Lewis acidic platinum(II) complexes as catalysts for the hetero Diels-Alder reaction

Bis-triflate diphosphine complexes of Pt(II) can be used as catalysts for the hetero Diels-Alder reaction (DA) between simple dienes (isoprene, 2,3-dimethylbutadiene) and glyoxylate esters or simple aldehydes (benzaldehyde, terephthalaldehyde) to yield a variety of substituted dihydropyrans under mild conditions. The reactions produces also hetero-ene products, but the selectivity to hetero Diels-Alder is always high (75-100%). Chiral catalysts based on R-binap yield only low e.e.'s.

NMR structure of an unusual Pt2(μ-BINOL) dimer: More surprises from a seemingly simple chiral ligand

A novel [(dppe)2Pt2(μ-BINOL)]2+[OTf]2 - dimer (A) was cleanly produced by addition of 1 equiv of HOTf to (dppe)Pt(S-BINOL) (1) or via comproportionation of 1 with (dppe)Pt-(OTf)2 (2). The structure of A was investigated by 1H, 31P, and 13C NMR spectroscopy, as well as 2D 1H/1H (COSY) and 13C/1H (HMQC, HMBC) correlation experiments, revealing that both halves of the bridging BINOL ligand have undergone enol-keto tautomerization in this complex. Two symmetry-equivalent (dppe)Pt fragments coordinate in an anti fashion via Pt-C σ bonds to the adjacent atoms C1 and C1′ of the resulting diketo BINOL ligand. η1-Coordination of the carbonyl groups of diketo BINOL to Pt was proposed to fill the fourth coordination site of each Pt square plane in dimer A, generating favorable five-membered Pt-chelate rings; the P-Pt coupling constants observed for A are consistent with C=0→Pt coordination. The driving force for dimer formation is likely electrostatic, as dimerization distributes the dicationic charge of Pt Lewis acid 2 over two Pt centers, facilitated by the diketo BINOL bridge.

Cationic complexes of palladium(II) and platinum(II) as Lewis acid catalysts for the Diels-Alder reaction

The synthesis of a series of Pd(II) and Pt(II) cationic complexes of the types [(P-P)M(solv)](Y)2, [(P-P)M(η2-Y)](Y), and [(P-P)M(μ-Cl)]2(Y)2 (where P-P = various diphosphines including chiral diphosphines (M = Pd, Pt; Y = TfO-, ClO4-, BF4-) is reported. All complexes are excellent catalysts for the Diels-Alder reaction between cyclopentadiene or cyclohexadiene and a number of simple dienophiles such as acrolein, methacrolein, and methylvinyl ketone. Some of the complexes modified with chiral diphosphines can act as enantioselective catalysts in the Diels-Alder reaction under mild condition with moderate ee's. A critical point in this respect is the presence of only one vacant coordination site in the catalyst.