Development of New Synthetic Reactions by Use of Acylzirconocene Complexes

研究了不同催化条件下酰基氯化锆和烯基氯化锆配合物的亲核反应。在Yb(OTf)_3/ tmsotf催化条件下，通过酰基锆新世氯化物与n -苄基苯胺衍生物的反应直接获得α-氨基酮衍生物，其中酰基锆新世氯化物作为“暴露”的酰基阴离子供体反应。用Bronsted酸代替Yb(OTf)_3/TMSOTf进行了上述反应。由乙醛、苯胺和酰基氯化锆组成的简单三组分反应基本上在没有催化剂的情况下产生α-氨基酮衍生物。酰基氯化锆配合物在Pd-Me_2Zn（Me_2AlCl）催化条件下与ω-不饱和α、β-烯酮和-炔酮反应生成立体选择性双环[3.3.0]化合物。采用[RhCl(cod)]_2催化剂，可有效地实现烯基锆茂氯配合物与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。由欧泊尔苏旦与2-丁烯酰氯反应得到的α，β-烯酸酰胺具有较高的非对映选择性，而用Evans的手性恶唑烷酮代替欧泊尔苏旦的手性助剂具有较差的非对映选择性。[RhCl(COD)]_2 （2mol%）催化的烯基锆茂氯配合物与N-Ts、-PO(OEt)_2和COOR醛胺衍生物的反应也在室温下在二氧六烷中高效进行，得到了收率很高的烯丙基胺衍生物。这是烷基锆茂氯配合物催化加成反应到醛胺衍生物的第一个例子。

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.