cycloadditions

简明释义

英[ˌsaɪkloʊædˈɪʃənz]美[ˌsaɪkloʊædˈɪʃənz]

n. 环加（cycloaddition 的复数）

英英释义

单词用法

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例句

1.The regioselectivity and site selectivity of above cycloadditions can be elucidated by FMO theory.

用前线分子轨道（FMO）理论可以说明上述反应的区域选择性与位置选择性。

2.The regioselectivity and site selectivity of above cycloadditions can be elucidated by FMO theory.

用前线分子轨道（FMO）理论可以说明上述反应的区域选择性与位置选择性。

3.The Diels-Alder reaction is a classic example of cycloadditions that forms six-membered rings.

狄尔斯-阿尔德反应是一个经典的环加成反应示例，它形成六元环。

4.In polymer chemistry, cycloadditions can be used to create complex molecular structures.

在聚合物化学中，环加成反应可用于创建复杂的分子结构。

5.Understanding cycloadditions is crucial for developing new pharmaceuticals.

理解环加成反应对于开发新药物至关重要。

6.Researchers are exploring the mechanisms behind cycloadditions to improve reaction yields.

研究人员正在探索环加成反应背后的机制，以提高反应产率。

7.The study of cycloadditions has led to new synthetic methods in organic chemistry.

对环加成反应的研究为有机化学中的新合成方法提供了支持。

作文

Cycloadditions are a fascinating class of chemical reactions that play a significant role in organic chemistry. These reactions involve the formation of cyclic compounds through the addition of two or more unsaturated molecules. The term 'cycloaddition' refers to the process where multiple reactants combine to form a ring structure, which is particularly important for synthesizing complex molecules found in natural products and pharmaceuticals. One of the most well-known types of cycloaddition is the Diels-Alder reaction, where a conjugated diene reacts with a dienophile to create a six-membered ring. This reaction is not only valuable for its efficiency but also for the stereochemistry it can introduce into the final product.The significance of cycloadditions (环加成反应) lies in their ability to construct intricate molecular architectures in a single step. This characteristic makes them highly desirable in synthetic organic chemistry, where the goal is often to achieve complex structures with minimal steps. For instance, in drug development, the ability to create cyclic compounds can lead to the discovery of new therapeutic agents. Many biologically active compounds contain cyclic structures, which are essential for their biological activity.Moreover, cycloadditions (环加成反应) are not limited to just the Diels-Alder reaction. There are several other types, including the [2+2] and [3+2] cycloadditions, which involve different numbers of reactants and result in various ring sizes. Each type of cycloaddition has its own unique mechanism and conditions under which it operates. Understanding these mechanisms is crucial for chemists as they design reactions and predict outcomes.In addition to their synthetic utility, cycloadditions (环加成反应) are also a topic of theoretical interest. Chemists study these reactions to understand the underlying principles of reactivity and selectivity in organic compounds. Theoretical models and computational chemistry have provided insights into the transition states and intermediates involved in these reactions, allowing for better predictions of reaction outcomes.Despite their advantages, cycloadditions (环加成反应) can also present challenges. For example, controlling the regioselectivity and stereoselectivity of the reaction can be difficult, especially when multiple products are possible. Researchers continue to explore new catalysts and reaction conditions to improve the efficiency and selectivity of these reactions.In conclusion, cycloadditions (环加成反应) are a vital part of organic chemistry, offering a powerful tool for constructing cyclic compounds. Their importance in synthetic chemistry, drug development, and theoretical studies cannot be overstated. As research in this area continues to evolve, we can expect to see even more innovative applications and discoveries stemming from these remarkable reactions.