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[摘要]：An effective, recoverable, dinuclear palladium(I) catalyst [(OCH(2)CMe(2)CH(2)O)PSPd(PPh(3))](2) has been explored and compared with other traditional palladium catalysts (e. g., [Pd(PPh(3))(4)]) in the phosphonylation/phosphanylation of allenes (OCH(2)CMe(2)CH(2)O)P(O)CH=C=CH(2) (1), Ph(2)P(O)CH=C=CH(2) (2), (EtO)(2)P(O)CH=C=CH(2) (3) (OCH(2)CMe(2)CH(2)O)P(O)CH=C=CMe(2) (4), Ph(2)P(O)CH=C=CMe(2) (5), (OCH(2)CMe(2)CH(2)O)P(O)C(Ph)=C=CH(2) (6) and Ph(2)P(O)C(Ph)=C=CH(2) (7). The phosphonylation/phosphanylation, in general, occurred at the carbon beta to the phosphorus atom, but the concomitant proton addition took place at the alpha or gamma positions leading to either allyl- or vinyl-phosphonates. The use of P(nBu)(3) as catalyst led to geminal and bis-phosphonylation/phosphanylation with less substituted =CH(2) terminal allenes 1 and 2. In conjunction with the use of the corresponding isomeric alkynes 8 and 9, as many as five different types of phosphonylated products have been synthesized. The reactions with the more substituted allenes 4-7 gave single products in most cases. Several examples of catalyst-free, solvent-free phosphanylation reactions are also described. The reactivity of the phosphonylating/phosphanylating agents was found to be (OCH(2)CMe(2)CH(2)O)P(O)H (10) < (OCH(2)CMe(2)CH(2)O)P(S)H (11) < Ph(2)P(O)H (12) approximate to Ph(2)P(S)H (13). The catalytic activity of the recoverable dinuclear palladium(I) complex [(OCH(2)CMe(2)CH(2)O)PSPd(PPh(3))](2) (14), which poses interesting questions about the mechanistic pathway, is briefly highlighted. Structures of the dinuclear palladium(I) catalyst 14 and the key products were determined by X-ray crystallography. |
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