[6737-42-4]  · C27H26P2  · 1,3-Bis(diphenylphosphino)propane  · (MW 412.45)

(ligand for metal-catalyzed substitution reactions of aryl and vinyl triflates,1 halides,2 and carbonates;3 carbonylation reactions;4 Grignard coupling;5 diene alkylation;6 macrocycle synthesis7)

Alternate Name: dppp.

Physical Data: mp 63-65 °C.

Form Supplied in: white solid; widely available.

Handling, Storage, and Precautions: solutions are readily oxidized to the phosphine oxide and should be handled under N2 or Ar. Solid samples of dppp are air stable.

Substitution Reactions.

Metal complexes of dppp catalyze the substitution of aryl triflates with a variety of reagents. A palladium complex of dppp catalyzes the deoxygenation of phenols via the corresponding triflate (eq 1).1 A variety of functional groups can be introduced, including acetyl,2 vinyl,8 and phosphoryl9 substituents. These reagents also catalyze the substitution reaction of aryl bromides with vinyl ethers (eq 2).2 A palladium-dppp complex has been used for the conversion of allylic carbonates to sulfides (eq 3).3

Carbonylation Reactions.

Palladium-dppp complexes catalyze the high-pressure carbonylation of allylic amines to give the corresponding amides (eq 4).4 Aryl triflates undergo carbonylation in MeOH with the formation of the methyl ester (eq 5).10 In the presence of alkynes, vinyl triflates are carbonylated to produce alkynyl vinyl ketones.11 Aldehydes are decarbonylated in high yield by dppp in the presence of Carbonyl(chloro)bis(triphenylphosphine)rhodium(I) (eq 6).12

Grignard Coupling Reactions.

The coupling of aryl and alkyl halides with Grignard reagents is efficiently catalyzed by Ni complexes of dppp (eq 7).5 The substitution of vinyl sulfides with Methylmagnesium Bromide in the presence of Dichlorobis(triphenylphosphine)nickel(II) and dppp leads to alkenes.13

Diene Alkylation.

Nucleophilic addition of b-dicarbonyl enolates to dienes is catalyzed by Pd-dppp and NaOMe (eq 8).6

Macrocycle Synthesis.

The intramolecular, palladium-catalyzed reaction of allylic carbonates with substituted ethers produces macrocycles in high yield (eq 9).7 The formation of 11- and 14-membered rings has been reported using dppp in combination with Tetrakis(triphenylphosphine)palladium(0).7,14 Intermolecular reactions have also been reported.

1. Saa, J. M.; Dopico, M.; Martorell, G.; Garcia-Raso, A. JOC 1990, 55, 991.
2. Cabri, W.; Candiani, I.; Bedeschi, A.; Santi, R. TL 1991, 32, 1753.
3. Trost, B. M.; Scanlan, T. S. TL 1986, 27, 4141.
4. Murahashi, S.; Imada, Y.; Nishimura, K. CC 1988, 1578.
5. Kumuda, M.; Taqmao, K.; Sumitani, K. OSC 1988, 6, 407.
6. Trost, B. M.; Zhi, L. TL 1992, 33, 1831.
7. Trost, B. M.; Ohmori, M.; Boyd, S. A.; Okawara, H.; Brickner, S. J. JACS 1989, 111, 8281.
8. Cabri, W.; Candiani, I.; Bedeschi, A.; Santi, R. JOC 1992, 57, 3558.
9. Kurz, L.; Lee, G.; Morgans, D.; Waldyke, M. J.; Ward, T. TL 1990, 31, 6321.
10. Dolle, R. E.; Schmidt, S. J.; Kruse, L. I. CC 1987, 904.
11. Ciattini, P. G.; Morera, E.; Ortar, G. TL 1991, 32, 6449.
12. Tsuji, J.; Ohno, K. TL 1965, 3969.
13. Ukai, J.; Ikeda, Y.; Ikeda, N.; Yamamoto, H. TL 1984, 25, 5173.
14. Trost, B. M.; Granja, J. R. JACS 1991, 113, 1044.

Gregory T. Whiteker

Union Carbide Corporation, South Charleston, WV, USA

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