Triphenylphosphine polystyrene bound

The cobalt(O) complex shown in Entry 2 (Table 3.49) could be prepared either by heating a mixture of an alkyne cobalt carbonyl complex with polystyrene-bound tri-phenylphosphine, or by pretreating resin-bound triphenylphosphine with dicobalt octacarbonyl and then treating the resulting support with the alkyne. 

Preparation of 4-(2-hromoethyl)phenol 200 [125] A solution of 4-(2-hydrox-yethyl)-phenol 201 (25 g, 0.181 mol, 1 equiv.), carbon tetrabromide (90.14 g, 0.272 mol, 1.5 equiv), and diphenylphosphino-polystyrene 33 (151 g, 0.453 mol, 2.5 equiv. triphenylphosphine polymer-bound 3mmolg Fluka Cat No. 93 093) in CH2CI2 (250 mL) was stirred at 40 °C for 3.5 h. The solution was then filtered, the resin was washed with CH2CI2 (3 x 175 mL), and the combined filtrate and washings were concentrated under reduced pressure to yield the title compound 200 as a white soHd (quantitative). 

The combination of polystyrene-bound triphenylphosphine and carbon tetrachloride has been used for the condensation of N-alkoxycarbonyl a-amino acids and primary amines, including amino acid esters, in the presence of N-methyl-morpholine as base and refluxing dichloromethane as solvent [56]. In this case, supported triphenylphosphane oxide was isolated by filtration after the coupling reaction. The nature of the intermediate involved in the condensation was supposed to be the acid chloride, as these derivatives are found when heating polystyrene-supported dichlorotriphenylphosphorane with carboxylic acids [57, 58], However, evidence supported by infrared spectroscopy suggests the formation of... 

Figure 8. 31P-CP/MAS solid-state spectrum of polymer-bound (polystyrene cross-linked with 2% divinylbenzene) triphenylphosphine (a), 31P-CP/MAS solid-state spectrum of cis-[PtCl2(PPht-C6H -CH—CH2)2] (referenced to external 85% Hs POJ (b), 31P-CP/MAS solid-state spectrum of a copolymer of 65% styrene, 31% divinylbenzene and 4% cis-/PtCl2(PPh2-C6H -CH CH2)z] after soxhlet extraction (c) and 31P-CP/MAS solid-state spectrum of c s-[PtCl(PPhs)2, (N P )] ClOf after soxhlet extraction (d). All spectra referenced to external 85% HsPOk. (Reproduced from Ref. 21. Copyright by American Chemical Society.)...

Polymer-supported triphenylphosphine ditriflate (37) has been prepared by treatment of polymer bound (polystyrene-2% divinylbenzene copolymer resin) triphenylphosphine oxide (36) with triflic anhydride in dichloromethane, the structure being confirmed by gel-phase 31P NMR [54, 55] (Scheme 7.12). This reagent is effective in various dehydration reactions such as ester (from primary and secondary alcohols) and amide formation in the presence of diisopropylethylamine as base, the polymer-supported triphenylphosphine oxide being recovered after the coupling reaction and reused. Interestingly, with amide formation, the reactive acyloxyphosphonium salt was preformed by addition of the carboxylic acid to 37 prior to addition of the corresponding amine. This order of addition ensured that the amine did not react competitively with 37 to form the unreactive polymer-sup-ported aminophosphonium triflate. 

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