Diphenylphosphine-potassium

Regarding the structure of the cyanoprene homopolymers (Table II), a trend becomes apparent when using the different catalyst systems. In a sample polymerized with diphenylphosphine lithium, 70% 1,2-linkages and about 30% 1,4-linkages were found, but the presence of traces of 3,4-adducts could not be excluded. There was no indication of cyclic structures although with stronger diphenylphosphine-potassium cyclic compounds were found. About 62% were 1,2-linkages while the remainder consisted of about equal parts of 1,4- and 3,4-adducts, the cyclic proportions included. 

To a stirred methylene chloride solution of 4.62 gm (15 mmoles) of 1-phenyl-2-(diphenylphosphine oxide)hydrazine maintained at —20°C is added over a 10 min period 2.67 gm (15 mmoles) of iV-bromosuccinimide. The solution is allowed to warm to room temperature, and stirring is continued for 10 min. The solids formed are removed by filtration and discarded. The solution is washed in turn with two portions of 5 % aqueous sodium thiosulfate solution, 0.1 N hydrochloric acid, water, dilute aqueous potassium bicarbonate, and again water. The methylene chloride solution is dried over anhydrous sodium sulfate and filtered. The filtrate is evaporated to incipient crystallization at room temperature at reduced pressure yield 4.1 gm (90%), m.p. 105°-106°C. 

Bis[l,2-bis(diphenylphosphine)ethane]-palladium(O), 34 Tributyl(iodomethyl)tin, 314 Other alkylations Dichlorodimethyltitanium, 216 Potassium fluoride, 256 (S)-Prolinol, 261... 

Lithium borohydride, 92 (lR,2S)-N-Methylephedrine-0-pro-pionate, 308 Norephedrine, 200 2-Oxazolidones, chiral, 225 (2R,4R)-Pentanediol, 237 Potassium triethylborohydride, 260 Other hydroxy carbonyl compounds (R)-( + )- and (S)-( - )-2,2 -Bis-(diphenylphosphine)-1,1 -binaphthyl, 36 Ketones... 

Poly di-/x- (diphenylphosphinato) aquohydroxychromium (III) has been prepared starting with chromium(II) acetate and an aqueous solution of potassium diphenylphosphinate. The chromium(II) diphenylphosphinate produced was then oxidized by exposure of an aqueous suspension to the air.1 The polymers... 

A solution of 51.2 g. (0.2 mole) of potassium diphenylphos-phinate in 1500 ml. of methanol is prepared as follows A suspension of 43.64 g. (0.2 mole) of diphenylphosphinic acid in 500 ml. of methanol is slowly neutralized by adding a solution of 16.3 g. (0.25 mole) of potassium hydroxide (assay 86.0% KOH) in 500 ml. of methanol until a pH of 6.5-7.0 is reached. The solution is then diluted to 1500 ml. with methanol and deaerated by passing a stream of nitrogen for 15 minutes through a gas dispersion tube immersed in the solution. 

The large dropping funnel attached to reaction flask B is filled with the potassium diphenylphosphinate solution. The solution is then allowed to enter the reaction flask slowly via stopcocks g and h while the contents of the flask are stirred continuously with the magnetic stirrer. The complete addition of the diphenylphosphinate solution should take approximately an hour. The blue-gray precipitate which forms rapidly at first assumes the bright pink color of chromium(II) diphenylphosphinate. Toward the end of the addition, the flow should be interrupted briefly and the supernatant liquid examined visually for the presence of excess chromium (II). A small excess of chromium(II) (blue color) should be present at the... 

A slight excess of potassium diphenylphosphine can open the oxetane ring of compound 190 to afford phosphine 191 (O Scheme 81) [126]. 

P,P,P, P -Tetraphenyl-p-phenylenediphosphine 218 (Chloro)diphenylphosphine (46 g, 0.2 mole) is dropped slowly into a dispersion of potassium (16 g, 0.4 mole) in dry tetrahydro-furan (250 ml) under nitrogen. The resulting deep red solution is treated, dropwise at room temperature, with a solution of p-dibromobenzene (24 g, 0.1 mole) in tetrahydrofuran (50 ml), and the mixture is heated for 8 h at 67°. After cooling, the product is hydrolysed with water (100 ml) and the organic phase is dried and freed from solvent. The residue is made into a slurry with ethanol and filtered off. The yield is 68% and the m.p. 170-171° (after recrystallization from propanol). 

S, 3 S)-l,4-Di-0-tosyl-L threitol (52), like the corresponding dimesylate 39, forms the bisepoxide 40 when treated with pulverized potassium hydroxide. Treating 40 with lithium diphenylphosphine followed by ketalization provides (2/ ,37 )-( —)-2,3-(9-isopropylidene-2,3-dihydroxy-l,4-bis(diphenylphosphino)butane (54) [( —)-DIOP] in a yield of 56% from 40 [26],... 

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