Formation of Phenylene Oligomers Using Platinum−Phosphine Complexes

Abstract

The reaction of biphenylene with a series of platinum bis-phosphine precursors [PtL 2 ] leads to a variety of C-H and C-C bond activation reactions. With L ) triethylphosphine, cleavage of the carbon-carbon bond of biphenylene has been shown to catalytically form tetraphenylene. With L 2 ) Bu t 2 PCH 2 PBu t 2 , the simple C-C cleavage of biphenylene is observed. With L ) PPh 2 Bu t , ortho metalation of the phosphine occurs to give a C-H activation product. Mechanistic details of these reactions are discussed. With L ) triphenylphosphine, however, biphenylene is not cleaved by the [L 2 Pt] fragment, but the independently prepared C-C insertion adduct does react with biphenylene to give five different products, including triphenylene, tetraphenylene, phenyltriphenylene, and hexaphenylene isomers.

Dibenzometallacyclopentadienes, boroles and selected transition metal and main group heterocyclopentadienes: Synthesis, catalytic and optical properties

“…The use of less basic PPh 3 , however, resulted in Pt/Pd complexes which were unreactive to C-C bond cleavage. Analogues can, however, be prepared by reacting [PtCl 2 (PPh 3 ) 2 ] with 2,2 -dilithiobiphenyl [24].…”

Dithiocarbazate complexes with the [M(PPh3)]2+ (M═Pd or Pt) moiety

“…[PtCl 2 (PPh 3 ) 2 ], benzyl dithiocarbazate, H 2 L 1a and H 2 L 2b were all prepared according to literature procedures [13,17,24,25]. [PdCl 2 (PPh 3 ) 2 ], 4-phenyl-2,4-butanedione, 2-hydroxyacetophenone and all solvents used were of reagent grade, purchased from commercial sources and used without further purification.…”

“…On the other hand, transition metal-phosphine complexes, especially with the platinum group elements, are considerably important for both industrial and laboratory scale catalytic applications [16][17][18]. In the literature there is a number of complexes of Pd(II) and Pt(II) with similar ligands, but few studies have been carried out on complexes having tridentate O,N,S-donor dithiocarbazate ligands and having triphenylphosphine in the fourth coordination site [19][20][21][22][23].…”

Backbone modified small bite-angle diphosphines: Synthesis and molecular structures of [M(CO)4{X2PC(R1R2)PX2}] (M=Mo, W; X=Ph, Cy; R1=H, Me, Et, Pr, allyl, R2=Me, allyl)

“…After mixing, slow evaporation yielded crystals suitable for X-ray diffraction. 1 (21). To 17 (0.19 g, 0.3 mmol) in thf (20 ml) was added nBuLi (0.49 ml, 1.2 mmol) causing the solution to turn dark yellow.…”