PREPARATION OF CONJUGATED HETEROCYCLES BY [4pi+6pi] CYCLOADDITION OF MESOIONIC COMPOUNDS

介离子化合物[4pi 6pi]环加成制备共轭杂环

• 批准号: 03640446
• 负责人: KATO Hiroshi
• 金额: $ 1.28万
• 依托单位: SHINSHU 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: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03640446/
• 关键词: Mesoionic; Tropone; Fulvene; Cycloaddition; Selectivity; Periselectivity; Ylide; 4+6; 周辺選択性

The in situ formation of a mesoionic 4-oxazolone allowed the formation of the [4pi+6pi] cycloadduct with tropone in good yield. The yields of a pyrazolotropone via [4pi+2pi] cycloadducts of a sydnone and the[4pi+6pi] adduct with a 1,3-dithiolone were increased by addition of copper(II) acetate.The reaction of mesoionic 5-thiazolones with tropone gave products by deep-seated rearrangement of the cycloadduct. The interrelationship among the products as well as the structures have been discussed.Theoretical consideration of the regio- and peri-selectivities of these cycloadditions based on PM3-MO calculation has led to the conclusion that the selectivity is governed mainly by steric factors and not by electronic interaction.A series of photoisomerization of a [4pi+6pi] adduct of a mesoionic 4-oxazolone with tropone was discovered. The structures of the products and mechanism leading to the photoproducts have been elucidated.A useful method for a practical preparation of 2-t-butyl-6-(dimethylamino)-fulvene has been established. This fulvene reacted with a sydnone, mesoionic 1,3-dithiolone, 1,3,2-oxathiazolone, and 4-oxazolone in a [4pi+6pi] mode. The cycloadducts underwent extrusion of a group of atoms and elimination of dimethylamine under the reaction conditions to give the desired fully unsaturated cyclopenta-thiapyrane, -pyridazine, -thiazine, and -pyrane derivatives, in one step and generally in good yields. These products have been found to have electronic structures isoelectronic with azulene.

原位形成的介离子4-恶唑酮允许形成的[4pi+6pi]环加合物与托品酮在良好的产率。通过加入乙酸铜（II），可提高5-噻唑酮与环酮的[4pi+2 pi]环加成物和1，3-二硫杂环戊烯酮的[4pi+6pi]环加成物的产率，并通过环加成物的深度重排得到吡唑并环庚酮。结果表明，环加成反应的选择性主要受空间位阻因素的影响，而不受电子相互作用的影响; 4-恶唑酮与托品酮的[4pi+6pi]加合物发生了一系列光异构化反应.对产物的结构和形成机理进行了初步的探讨，为2-叔丁基-6-二甲氨基富烯的合成提供了一种实用的方法。该富烯以[4pi+6pi]模式与悉尼酮、介离子1，3-二硫杂环戊烯酮、1，3，2-恶唑酮和4-恶唑酮反应。在反应条件下，环加合物经历了一组原子的挤出和二甲胺的消除，以在一个步骤中并且通常以良好的产率得到所需的完全不饱和的环戊-噻喃、-哒嗪、-噻嗪和-吡喃衍生物。已发现这些产物具有与甘菊环等电子的电子结构。

项目成果

加藤 博: "Heterocycles by cycloaddition.[4π+2π]and[4π+6π]cycloadditions of mesoionic compounds to tropone" J.Chem.Soc.,Perkin I.

Hiroshi Kato：“通过环加成形成杂环。介离子化合物与托酮的[4π+2π]和[4π+6π]环加成”J.Chem.Soc.，Perkin I.

加藤博,小林知重,徳江和彦,白沢園子: "Heterocycles by cycloaddition.Part II.Dipolar cycloadditions of mesoionic compounds with tropone.Periselective[4π+2π]and[4π+6π]cycloadditions" J.Chem.Soc,.Perkin Trans.1.(1993)

Hiroshi Kato、Tomoshige Kobayashi、Kazuhiko Tokue、Sonoko Shirasawa：“环加成杂环。第二部分。介离子化合物与托酮的偶极环加成。全选择性[4π+2π]和[4π+6π]环加成”J.Chem.Soc，。传1.(1993)

Hiroshi Kato, Tomoshige Kobayashi, Kazuhiko Tokue, and Sonoko Shirasawa: "Heterocycles by cycloaddition. Part 11. Dipolar cycloadditions of mesoionic compounds with tropone. Periselective [4pi+2pi] and [4pi+6pi] cycloadditions." J. Chem. Soc., Perkin Tran

Hiroshi Kato、Tomoshige Kobayashi、Kazuhiko Tokue 和 Sonoko Shirasawa：“环加成杂环。第 11 部分。介离子化合物与托酮的偶极环加成。近选择性 [4pi 2pi] 和 [4pi 6pi] 环加成。”

加藤 博、小林 知重 徳江 和彦、白沢 園子: "Heterocycles by cycloaddition.Part11.Dipolar cycloadditions of mesoionic compounds with tropone.Periselective[4π+2π]and[4π+6π]cycloadditions" J.Chem.Soc.,Perkin Trans.1.(1993)

Hiroshi Kato、Tomoshige Kobayashi、Kazuhiko Tokue、Sonoko Shirasawa：“环加成的杂环。第 11 部分。介离子化合物与托酮的偶极环加成。周选择性 [4π+2π] 和 [4π+6π] 环加成”J.Chem.Soc.，Perkin Trans .1.(1993)