Palladium-Catalyzed Acylcyanation of Terminal Arylacetylenes. Synthesis of 1,3-Diaryl-3-cyano-2-propen-1-ones and Tetrasubstituted Furans
作者:Kyoko Nozaki、Naomasa Sato、Hidemasa Takaya
DOI:10.1246/bcsj.69.1629
日期:1996.6
zero-valent palladium metal has been observed by admixture of 4-MeOC6H4COCN to Pd2(dba)3 · CHCl3–PPh3–0.5dppb oxide (dppb oxide = Ph2P(O)(CH2)4P(O)Ph2). The resulting Pd(4-MeOC6H4CO)(CN)(PPh3)(ligand) afforded (Z)-1c by reaction with phenylacetylene. Thus, the role of two kinds of phosphine, PPh3 and dppb, suggests that the former acts as a ligand and the latter works as a reductant of Pd(II). The product
(Z)-1,3-Diaryl-3-cyano-2-propen-1-ones ((Z)-1) 在 Pd(OAc)2–PPh3 (1 mol amt. to Pd)–0.5dppb(1,4-双(二苯基膦基)丁烷)(0.5 mol amt. to Pd)。该反应通过形成炔酮 3 进行,然后在钯催化下加入 HCN,并将所得 (E)-1 异构化为 (Z)-1。通过将 4-MeOC6H4COCN 与 Pd2(dba)3 · CHCl3–PPh3–0.5dppb 氧化物混合(dppb 氧化物 = Ph2P(O)(CH2)4P(O)Ph2)观察到芳烃羰基氰化物氧化加成到零价钯金属)。所得Pd(4-MeOC6H4CO)(CN)(PPh3)(配体)通过与苯乙炔反应得到(Z)-1c。因此,两种膦 PPh3 和 dppb 的作用表明,前者充当配体,而后者充当 Pd(II) 的还原剂。产物 (Z)-1 在室温下在