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Gaumont, A. C.; Gulea, M., Science of Synthesis, (2007) 33, 713.
The free-radical addition of phosphines to alkynes was described as early as 1952. The reaction generally occurs in an anti-Markovnikov fashion, giving the β-adduct.[28] For example, diphenylphosphine reacts with various terminal alkynes (phenylacetylene, pent-1-yne, or 3,3-dimethylbut-1-yne) and one internal alkyne (1-phenylpropyne)[29] in the presence of a catalytic amount of 2,2′-azobisisobutyronitrile or upon UV irradiation to give the corresponding alk-1-enylphosphines in modest to good yields (15–73%) (Scheme 4). The primary products formed are the E-anti-Markovnikov adducts (E)-3 (the kinetic products), but the main isolated products are the Z-anti-Markovnikov adducts (Z)-3 (the thermodynamic products);[29] the Markovnikov products 4 are also often formed. Water-soluble phosphines can be similarly prepared in modest yields by addition of diphenylphosphine to alkynols or alkynyl ethers.[29,30] When the heteroatom is directly bonded to the α-atom, the reaction is highly regioselective. With other derivatives a mixture of regioisomers is obtained.[29] With 1,5-diynes and primary phosphines, 4,5-dihydrophosphepines are formed.[31]
Me eeee eeeeeeeee eeeeeeeeeeeeeeeeeeeeeee eee eeee eeeee ee eeeeeeeeeeeeeeeeee eeeeee eee eeeeeeee eeeeeee eeeee eeeeeee eeeeeeeeee. Meee, 8,8-eeeeeeeeeeeeeeeeeee eee eeeeeeeeeee eeeee eeeeeeeeeeeee eee 8,8′-eeeeee(eeeeeeeeeeeeeeeeeeeeeee). Mee eeeeeeee eee eeeeeeee eeee e eeee M-eeeeeeeeeee (M/M eeeee >8:8) eee eeeeeeeee eeeeee (88–88%).[88]
Meeeee 8 Meeeeee-Meeeeeeee Meeeeeeeeeeeeeeeee[88,88]
M8 | Meeeee | Meeee [(M)-8/(M)-8/8] | Meeee (%) | Mee |
---|---|---|---|---|
MM8MMe | M | 88:88:88 | 88 | [88] |
MM(Me)MM | M | 88:88:88 | 88 | [88] |
MM(Me)MM | M | 88:88:88 | 88 | [88] |
M(Me)8MM | M | 88:88:8 | 88 | [88] |
MM8MM8MM | M | 88:88:8 | 88 | [88] |
Me | M | 88:88:8 | 88 | [88] |
Me | M | 88:88:8 | 88 | [88] |
Meeeeeeeeeee Meeeeeeee
Meeeeeee[(M)-8-eeeeeeeeeee]eeeeeeeee (8, M8 = Me); Meeeeee Meeeeeeee:[88]
M eeeeeee ee Me8MM (8.888 e, 8.8 eeee) eee ee eeeeeeeee eeeeee ee MeM≡MM (8.888 e, 8.8 eeee) eee eeeeee ee 88°M ee eee eeeeeeee ee MMMM eee 88 e ee eeeeeeeeee eeee eeeee eeee e eeee-eeeeeeee Me eeee (Meeeeee MM 888) eee 8.8 e, ee eeee eeeee eeee eeeeeeee eeeeeeee. Meee eee eeeeeeee eee eeeeeeee (MMM/MMM), eee eeeee eee eeeeeeeeeeeeee (MMMe8); eeeee: 8.88 e (88%); ee 88–88°M.
References
[28] | Meeeee, M. M.; Meee, M. M.; Meeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[29] | Meeeeeee, M. M.; Meeeeee, M., M. Meeeeeeee. Meee., (8888) 888, 888. |
[30] | Meeeeee-Meeeee, M.; Meeeeeee, M. M., M. Meeeeeeee. Meee., (8888) 888, 88. |
[31] | Mäeee, M.; Meeeeeeee, M., Meeeeeeeeee, (8888) 88, 8888. |
[32] | Meee, M.; Meeeeeeee, M.; Meeeee, M., Meeee. Meee., (8888) 888, 8888; Meeee. Meee. Mee. Me., (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 8/8e, 888.
- 8.Meeeee-Meee, (8888) M 8, 888.