Search for New Synthetic Reactions using Acylzirconocene Complex as an "Unmasked" Acyl Anion

在我们正在进行的酰基锆新世配合物合成新反应的研究项目中，我们已经开发了酰基锆新世配合物用于有机合成的巨大可能性。在过去的项目期间，我们建立了几个相当新的合成反应，其中酰基二茂锆氯在化学计量量的刘易斯酸存在下与醛反应，得到a-酮醇衍生物。这是第一个酰基氯化锆作为“暴露”酰基阴离子反应的例子。我们还发现了一个pd催化的酰基二茂锆氯与有机卤化物的反应，得到酮衍生物。此外，在pd催化条件下，酰基锆新世配合物对α， β-不饱和酮具有区域选择性。在1,2 -选择性加成条件下，首次利用手性膦配体实现了“暴露”酰基阴离子的对映选择性加成。虽然本反应的不对称诱导率（66% ee）还不够高，但我们目前正在继续研究寻找更有效的手性配体用于锆金属配合物。

In our ongoing research project on new synthetic reactions using acylzirconocene complex, we have exploited enormous possibilities of acylzirconocene complex for organic synthesis. During the past term of the project we established several quite new synthetic reactions in which acylzirconocene chloride reacted with aldehyde in the presence of a stoichiometric amount of Lewis acid to give a-ketol derivatives. It is the first example that the acylzirconocene chloride reacts as an "unmasked" acyl anion. We also found a Pd-catalyzed reaction of acylzirconocene chloride with organic halides to give ketone derivatives. Moreover, in the Pd-catalyzed conditions, acylzirconocene complex adds to α, β-unsaturated ketones, regioselectively. In the 1, 2-selective addition conditions, an enantioselective addition of the "unmasked" acyl anion was achieved for the first time by the use of chiral phosphine ligand. Although the asymmetric induction (66% ee) in the present reaction is not satisfactorily high yet, we are currently continuing the research to find more effective chiral ligand for zirconium metal complex.