Study on Stereocontrol in Sigmatropic Rearrangement

Sigmatropic重排立体控制研究

• 批准号: 01540455
• 负责人: KATSUKI Tsutomu
• 金额: $ 1.09万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01540455/
• 关键词: Sigmatropic Rearrangement; [2, 3] Winttig Rearrangement; Kinetic Resolution; Concave-shaped Ligand; 〔2.3〕Wittig転位反応; ボ-ト型遷移状態; 複合ルイス酸; 〔2,3〕Wittig転位反応; アンチ選択性

i) Anti-selective [2, 3] Wittig rearrangementIn the course of the study on stereocontrol of sigmatropic rearrangements, we found that [2, 3] Wittig rearrangement of 2' -heterosubstituted alpha-alkenyloxyacetic acid esters exhibited unusual anti-selectivity as shown below. The origin of this unusual stereoselectivity was attributed to the steric repulsion of a ligand on the counter metal ion and a C2' -substituent and to interaction of lone pair orbital on oxygen atom and sigma^* -orbital of C2 -carbon and hetero atom bond.ii) Preparation of concave-shaped ligands and their application to kinetic resolution of dl-epoxy alcohols.Concave-shaped ligands (1 and 2) were prepared from L-alanine and their titanium complexes were used for kinetic resolution of dl-epoxy alcohols as Lewis acid catalyst. As shown in the following scheme, kinetic resolution of 3, 3-disubstituted epoxy alcohols using a combination of Ti (OPr^i) 4 and 1a was found to proceed with high efficiency.Further study on ester enolate Claisen rearrangement via titanium enolate wherein titanium ion carries 1 as a ligand, is under investigation.

i) 抗选择性[2, 3] Wittig重排在σ重排立体调控的研究过程中，我们发现2'-杂取代α-烯氧基乙酸酯的[2, 3] Wittig重排表现出异常的抗选择性，如图所示以下。这种不寻常的立体选择性的起源归因于配体对反金属离子和C2'-取代基的空间排斥以及氧原子上的孤对电子轨道与C2-碳和杂原子键的sigma^*-轨道的相互作用.ii) 凹形配体的制备及其在 dl-环氧醇动力学拆分中的应用。由 L-丙氨酸制备凹形配体（1 和 2）其钛配合物作为路易斯酸催化剂用于动态拆分dl-环氧醇。如下图所示，发现使用 Ti (OPr^i) 4 和 1a 的组合可以高效地进行 3, 3-二取代环氧醇的动力学拆分。通过钛烯醇化物进行酯烯醇化物 Claisen 重排的进一步研究，其中钛离子带有1作为配体，正在研究中。

项目成果

石川彰: "Sterically Controlled[2,3]Wittig Rearrangement of Isopropyl 2'-Heterosubstituted-2'-alkenyloxyacetates" Tetrahedron Letters.

Akira Ishikawa：“2-杂取代-2-烯氧基乙酸异丙酯的空间控制[2,3]维蒂希重排”四面体字母。

石川 彰: "Stereoelectronically Controlled [2,3]ーWitting Rearrangement of Isopropyl 2^´ーHeterosubstituted 2^´ーAlkenyloxyloxyacetates" Tetrahedron Letters. 31. 2415-2418 (1990)

Akira Ishikawa：“立体电子控制 [2,3]ー异丙基 2^´ー杂取代 2^´ー烯氧基氧基乙酸酯的维特重排”四面体快报 31. 2415-2418 (1990)

石川 彰: "Stereoelectronically Controlled [2,3]Wittig Rearrangement of Isopropyl 2^1ーHeterosubstituted 2^1ーAlkenyloxyacetates" Tetrahedron Letters. 31. 2415-2418 (1990)

Akira Ishikawa：“异丙基 2^1－杂取代 2^1－烯氧基乙酸酯的立体电子控制 [2,3]Wittig 重排”四面体快报 31. 2415-2418 (1990)

A. Ishikawa, H. Uchiyama, T. Katsuki, and M, Yamaguchi: "Stereoelectronically Controlled [2, 3] Wittig Rearrangement of Isopropyl 2' -Heterosubstituted- 2' -Alkenyloxyacetates" Tetrahedron Letters. 31-17. 2415-2418 (1990)

A. Ishikawa、H. Uchiyama、T. Katsuki 和 M, Yamaguchi：“异丙基 2-杂取代-2-烯氧基乙酸酯的立体电子控制 [2, 3] Wittig 重排”四面体字母。

石川 彰: "Kinetic Resolution of dlー2,3ーEpoxy Alcohols Using Chiral Titanium Complex with Amino Alcohol Derived Ligand" Tetrahedron Letters.

Akira Ishikawa：“使用手性钛配合物和氨基醇衍生配体动力学拆分 dl-2,3-环氧醇”四面体字母。