Organo halide addition to tris(bis(diphenylphosphino)methane)dipalladium. Preparation of novel methylene- and phenylene-bridged complexes by two-center, three-fragment oxidative addition

Abstract

Dihalomethanes react with Pd2(dpm)3 (dpm = bis(diphenylphosphino)methane) to form Pd2(dpm)2fii-CHR)X2

Facile Oxidative Addition of Organic Halides to Heteroleptic and Homoleptic Pd0–N‐Heterocyclic Carbene Complexes

“…The collected filtrates were stored in the freezer to give white solids and then recrystallized from n-hexane to give white crystals of 13 (0.149 g, 39 %). C 32 [{(Me 3 P)(SIPr)BrPd} 2 (μ-C 4 H 2 S-C 4 H 2 S)] (14): 5,5Ј-Dibromo-2,2Ј-bithiophene (0.066 g, 0.20 mmol) and THF (4 mL) were sequentially added to a Schlenk flask that contained 1 (0.239 g, 0.42 mmol) at room temperature. The initial insoluble material slowly dissolved to give a yellow solution.…”

“…The imidazoline ring is significantly twisted from the two 2,6-bis(isopropyl)phenyl rings with the dihedral angle of 73.54 (6) [25] which was prepared from [PdCl 2 (cod)] (cod = 1,2-cyclooctadiene), excess amounts of diazomethane or bis(chloromethyl)mercury, followed by the ligand replacement with PPh 3 . Although many cases of the thermal or photoinduced oxidative addition of dihalomethanes to low-valent Pt, [27][28][29][30] Pd, [24,[31][32][33] Rh, [34][35][36][37][38][39][40][41][42][43] Ru, [44] Ir, [45][46][47] Co, [48] and Au [49] complexes were reported, only a few cases have been known to date for zero-valent Pd complexes, including [Pd(PtBu 2 -H) 3 ], [24] [Pd(PCy 3 ) 2 (dba)] (dba = dibenzylideneacetone; Cy = cyclohexyl), [31] and [PdN(CH 2 CH 2 PPh 2 ) 3 ]. [28] Furthermore, there have been no reports for the structural characterization of the oxidative addition complex Cl-PdCH 2 Cl by X-ray diffraction.…”

Synthesis and spectroscopy of binuclear phosphine bridged palladium hydrides: Pd2HX3[dppm]2 (X=Br, I; dppm=bis[diphenylphosphino]methane)

“…After verifying the molar conductivity of Pd 2 I 2 (CH 3 ) 2 dppm 2 [16] in our apparatus, the molar conductivity of 1b (L M 0/1 cm 2 mol (1 V (1 ) suggests that the latter is a non-electrolyte in CH 2 Cl 2 . The molar conductivity of 1b is similar to that of Pd 2 I 2 dppm 2 and Pd 2 I 4 dppm 2 and much smaller than for Pd 2 I 2 (CH 3 ) 2 dppm 2 ( Table 2).…”

“…The difficulty with structures A and B is the low molar conductivity for 1b and our inability to exchange one of the halide ligands for PF 6 ( . The molar conductivity of 1b in CH 2 Cl 2 ( [16]. The molar conductivity of 1b is similar to that of Pd 2 I 2 dppm 2 (L M 0/0.2 cm 2 mol (1 V (1 ) and Pd 2 I 4 dppm 2 …”

“…][16]. The ambient temperature31 P{ 1 H}-NMR spectrum of [Pd 2 I(m-I)(CH 3 )dppm 2' ][BF 4-] closely resembles that of 1a,b below (/90 8C.…”