Further Studies on Nickel-Promoted or -Catalyzed Cyclization of 1,3-Diene and a Tethered Carbonyl Group
作者:Yoshihiro Sato、Masanori Takimoto、Miwako Mori
DOI:10.1021/ja991241d
日期:2000.3.1
A nickel-promoted intramolecular cyclization of 1,3-diene with the tethered carbonyl group was developed using the catalyst generated by reduction of Ni(acac)2 with DIBAL-H in the presence of PPh3. It was found that the addition of 1,3-CHD to the reaction mixture affected the regiochemistry of olefin on the side chain of the cyclized product. The reaction course of this cyclization can be accounted
使用通过在 PPh3 存在下用 DIBAL-H 还原 Ni(acac)2 生成的催化剂,开发了镍促进的 1,3-二烯与束缚羰基的分子内环化。发现向反应混合物中加入 1,3-CHD 会影响环化产物侧链上烯烃的区域化学。这种环化的反应过程可以通过两种可能的机制来解释。在一种机制中,镍氢化物配合物起关键作用,环化通过 π-烯丙基镍中间体进行。在另一种机制中,零价镍配合物是活性物质,环化通过镍环中间体进行。这些机制上的考虑导致发现了 1,3-二烯和束缚醛的两种镍 (0) 催化的环化反应,