Preparation, structure and coordination properties of 3,3-bis(diisopropylamino)-3-thioxo-1-(2,4,6-tri-tert-butylphenyl)-1,3-diphosphapropene

Abstract

(Z)-1-Chloro-2-(2,4,6-tri-tert-butylphenyl)-2-phosphaethenyllithium was allowed to react with bis(diisopropylamino)-phosphenium triflate to afford the corresponding 1,3-diphosphapropene which was converted to 3-thioxo-1,3-diphosphapropene [(Z)-Mes*P = C(Cl)-P(= S)(NiPr2)2]. The coordination properties of 3-thioxo-1,3'-diphosphapropene were investigated with carbonyltungsten(0) and dichloroplatinum(II) reagents, and the molecular structure of the chelate dichloroplatinum(II) complex was unambiguously determined by X-ray crystallography together with the free ligand. The dichloroplatinum(II) complex underwent intramolecular cyclisation involving C-H activation to give a 5,7-di-tert-butyl-3,3-dimethyl-l-(phosphinomethyl)-1-phosphaindane derivative as well.

vic‐Dichlorodiphosphapropenes – Synthesis and Coordination Ability

“…[5] Complexes 6 and 7 are the first examples of such rearrangement observed at a λ 3 σ 3 phosphorus atom during coordination at palladium (Figures 3 and 4). .…”

“…Tungsten complex 5 was obtained by addition and stirring at room temperature of diphosphapropene sulfide 2 to a solution of W(CO) 5 (thf) (Scheme 5). Scheme 5. After 2 h, the 31 P NMR spectrum showed near-quantitative formation of complex 5 ( Figure 2 Monitoring the reaction by 31 P NMR between -20°C and room temperature did not allow characterizing of any intermediate such as a compound with a monodentate ligand (coordinated to W either through S or P).…”

“…We report here the synthesis of such a new diphosphapropene, 3-tert-butyl-2,3-dichloro-1-(2,4,6-tri-tert-butylphenyl)-1,3-diphosphapropene (1), its oxidation products, 3-thioxo-(2), 3-oxo-(3), and another new 3-oxodiphosphapropene Mes*P=C(Cl)-P(O)(Cl)Mes (4). The reactions of 2 with W(CO) 5 (thf) and that of 1 and 2 with PdCl 2 (cod) are also discussed.…”

“…[3,6] It is interesting to note that no platinum or palladium complexes of Mes*P=C(Cl)-PPh 2 could be isolated so far. [4,5] The choice of substituents on phosphorus is important in terms of steric and electronic effects, as both influence the stability and reactivity of diphosphapropenes. We have been interested in diphosphapropenes with two different substituents on the λ 3 σ 3 (IIa) or the corresponding λ 5 σ 4 (IIb) phosphorus atom.…”

“…Monocoordinate complexes with W(CO) 5 and chelates with W(CO) 4 of I were obtained and characterized for the systems with R 1 R 2 = Ph 2 and X = Cl, [2] Me, [3] SiMe 3 . [6] Pt II and Pd II complexes with ligands bearing Me [3] or SiMe 3 [6] at the carbon atom of I were prepared, and tests on the catalytic activity in Sonogashira and Suzuki reactions showed some encouraging results.…”