通过光激活简单的基基乙烯 Ester 的光激活进行光激活的分子内 [2 + 2] 循环添加
Lewis McGhie1,2, Hannah M Kortman1,2, Jenna Rumpf1,2
1Biomolecular Systems Department, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.
Beilstein journal of organic chemistry
|May 7, 2025
概括
研究人员开发了一种使用高能敏化剂光激活简单基的新方法. 这一突破使得新的分子内循环添加能够产生复杂的3D结构,并使用柄进行进一步的反应.
科学领域:
- 有机化学 有机化学
- 摄影化学的使用.
- 催化剂是一种催化剂.
背景情况:
- 通过能量转移 (EnT) 催化对有机分子的光激活通常仅限于具有低能三重激发状态的结合系统.
- 简单的基对这些方法来说是一个重大挑战,限制了反应设计中的更广泛的应用.
研究的目的:
- 克服EnT催化对简单基的局限性.
- 开发一个新的平台,用于未来的反应设计,使用高能传感器.
- 为了实现光激活简单的基乙烯乙烯基 Ester.
主要方法:
- 使用基混杂作为快速反应探针来识别合适的催化剂和基因.
- 采用循环电压测量和紫外线光谱来确认敏感性.
- 执行控制反应以验证发现.
主要成果:
- 成功光激活了简单的基乙烯乙烯基 Ester.
- 确定了有效的高能敏化剂和最佳基因.
- 实现了分子内 [2 + 2] 循环添加反应.
结论:
- 开发的方法使以前具有挑战性的简单基的光激活成为可能.
- 反应提供了使用手柄功能化的3D自行车片段的访问.
- 这项工作为设计新型光化学反应提供了一个有吸引力的平台.
相关概念视频
Hydroboration-Oxidation of Alkenes
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
Cycloaddition Reactions: MO Requirements for Thermal Activation
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.

![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)