Über das Benzochinon‐triphenylphosphin (I. Mitteil. über Chinonphosphine)

Catalytic Polymerization of Ethylene in Aqueous Emulsion with a Simple in Situ Catalyst

“…For 2,6-dichloro-1,4-benzoquinone (DCBQ) and 2,3,5-trichlorobenzoquinone (TriCBQ), formation of a P∧O-chelated nickel(II) complex as the active species can be assumed on the basis of the known reaction of 1,4-benzoquinone with triphenylphosphine and of the resulting phosphorane with nickel(0) compounds (Scheme ) . This is also in accordance with the observed selectivity in the C−C linkage of ethylene for formation of linear polymer (vide infra), typical for P∧O-chelated nickel(II) complexes. 11d,e …”

“…As for the nature of the active species, the reaction of TetraCBQ with triphenylphosphine and 1 equiv of water has been reported to afford triphenylphosphine oxide and 2,3,5,6-tetrachlorohydroquinone, based on IR and UV analysis 11b. In agreement with this finding, for the in situ catalyst system, that is for a 1:1 mixture of TetraCBQ and triphenylphosphine in toluene/methanol, the formation of triphenylphosphine oxide was observed by 31 P NMR (δ = 32.3 ppm, assignment confirmed by enrichment with a genuine sample of Ph 3 PO).…”

Nucleophilic Phosphine Catalysis: The Untold Story

“…Believing that the mode of phosphine addition to carbon disulfide would apply to other similar electrophilic systems, Davies assigned structure 4 to the p ‐benzoquinone adducts of triethylphosphine, tributylphosphine, and dimethyl( p ‐tolyl)phosphine [9] . In the following year, Schönberg revised the structure formed from triphenylphosphine and p ‐benzoquinone to the “Schönberg adduct” 5 , based on the observation that its hydrolysis in NaOH solution produced dihydroquinone and triphenylphosphine oxide [11] . Maleic anhydride (and some of its substituted derivatives) exhibited reactivity similar to that of p ‐benzoquinone toward triphenylphosphine, forming a structure assigned to the adduct 6 .…”

“…[9] In the following year, Schönberg revised the structure formed from triphenylphosphine and p-benzoquinone to the "Schönberg adduct" 5, based on the observation that its hydrolysis in NaOH solution produced dihydroquinone and triphenylphosphine oxide. [11] Maleic anhydride (and some of its substituted derivatives) exhibited reactivity similar to that of pbenzoquinone toward triphenylphosphine, forming a structure assigned to the adduct 6. Schönberg reported that addition of as little as a single crystal of maleic anhydride or pbenzoquinone into a dilute solution of triphenylphosphine in chloroform immediately provided an orange-red or reddish brown solution, respectively; these processes were characterized as "sensitive color reactions".…”

Preparation and X-ray structure of a (catecholato)copper(II) complex with a Schönberg adduct

“…The product was first evidenced, after some uncertainties, as (trialkylphosphoniono)catechols and called as the ''Schö nberg adduct'' (1,2) (Scheme 2) [11][12][13][14][15][16][17].…”