Development of New Synthetic Reactions by Use of Acylzirconocene Complexes

研究了在不同催化条件下，酰基二茂锆络合物和烯基氯化锆络合物的亲核反应。在Yb(OTf)_3/α-SOTf催化条件下，通过酰基二茂锆氯化物与N-亚苄基苯胺衍生物的反应，直接获得了TMSOTf-氨基酮衍生物。用Bronsted酸代替Yb(OTf)3/TMSOTf作为催化剂，也进行了上述反应。由醛、苯胺和酰基二茂锆氯组成的操作简单的三组分反应基本上在没有催化剂的情况下提供了α-氨基酮衍生物。在Pd-Me_2ZN(Me_2AlCl)催化条件下，酰基二茂锆氯化物与ω-不饱和α，β-烯酮和-酮反应，得到立体选择性的双环[3.3.0]化合物。α，β-烯酮、α，β-烯酸酯和α，β-烯酸酰胺的1，4-共轭加成反应均可在[Rh-Cl(Cod)]_2催化剂上实现。由Oppolzer磺胺衍生的α，β-烯酸酰胺与2-丁烯酰氯反应得到了较高的非对映选择性，而用Evans手性恶唑烷酮代替Oppolzer舒坦手性助剂的非对映选择性较差。在二氧六环中，[RhCl(COD)]_2(2mol%)催化的烯基二茂锆衍生物与N-ts、-PO(OEt)_2和乙二胺衍生物的反应也能有效地进行，并以较高的产率得到烯丙基胺衍生物。这是第一个烯基氯化锆络合物与乙二胺衍生物的催化加成反应的例子。

Nucleophilic reactions of acylzirconocene chloride and alkenyl zirconocene chloride complexes under a variety of catalytic conditions have been investigated. Direct access of α-amino ketone derivatives through reaction of acylzirconocene chlorides with N-benzylideneaniline derivatives in which acylzirconocene chlorides react as an "unmasked" acyl anion donor, was carried out under Yb(OTf)_3/TMSOTf-catalyzed conditions. The same above reactions were also carried out with the use of Bronsted acid as a catalyst in place of Yb(OTf)_3/TMSOTf. The operationally simple three-component reaction comprised of aldehyde, aniline and acylzirconocene chloride affords α-amino ketone derivatives essentially in the absence of a catalyst. Acylzirconocene chloride complex reacts with ω-unsaturated α,β-enones and -ynones under Pd-Me_2Zn(Me_2AlCl) catalyzed conditions to give stereoselectively bicyclo[3.3.0]compounds. The 1,4-conjugated addition of alkenylzirconocene chloride complexes to α,β-enones, α,β-enoic acid esters, and α,β-enoic acid amides can be efficiently achieved by the use of [RhCl(cod)]_2 catalyst. A high diastereoselectivity was obtained through the reaction of α,β-enoic acid amide derived from Oppolzer's sultam and 2-butenoyl chloride, while the use of Evans' chiral oxazolidinone as a chiral auxiliary in place of Oppolzer's sultam gave a poor diastereoselectivity. [RhCl(COD)]_2 (2mol%)-catalyzed reactions of alkenylzirconocene chloride complexes to N-Ts, -PO(OEt)_2 and COOR aldimine derivatives also proceeded efficiently in dioxane at room temperature to give allylic amine derivatives in excellent yields. This was the first example of the catalytic addition reactions of alkenylzirconocene chloride complexes to aldimine derivatives.