环化反应（Cyclization reaction）是指在有机化合物分子中形成新的碳环或杂环的反应，也称闭环或成环缩合。 在形成碳环时，是以形成碳—碳键来完成环合反应的；在形成含有杂原子的环状结构时，它可以是以形成碳—碳键的方式来完成环合反应，也可以是以形成碳—杂原子键（C-N、C-O、C-S键等）来完成环合反应，有时也可以是在两个杂原子之间成键（N-N、N-S键等）来完成环合反应。 环化反应的类型很多，且所用的反应剂也很多，因而没有统一的反应通式，也不能 …

Radical cyclization reactions are organic chemical transformations that yield cyclic products through radical intermediates. They usually proceed in three basic steps: selective radical generation, radical cyclization, and conversion of the cyclized radical to product.

Sep 13, 2022 · Transition-state structures for radical addition and radical cyclization are given in Figure 6 in a general form. For cyclization reactions not only ring size but also ring conformation affect trans­i­tion-state energy; thus, both chair-like 25,27 and boat-like 27,30 structures are possible during five-mem­bered ring formation.

A cyclization reaction refers to the formation of a ring compound from a chain by the creation of a new bond. This reaction plays a crucial role in organic synthesis for the design of efficient cyclization reactions.

Cyclization is an ancient and effective method to improve the protease stability of AMPs. Stabilizing the structure of conformational restriction through cyclization can make the packing of amino acid side chains more compact and slow down the cleavage effect of protease through forming steric hindrance.

From 2, 6-dichloropyridine as starting material, we can get the target molecule through nitration, substitution, reduction, cyclization, oxidation etc.以2,6 -二氯吡啶为原料，通过硝化，取代，还原，环化，氧化等几步反应可得到目标化合物。 [1]

Apr 26, 2017 · Some of the most dramatic structural alterations in natural product biosynthesis occur through oxidative cyclization. In this Review, we examine the different strategies used by nature to create new intra(inter)molecular bonds via redox chemistry.

Mar 4, 2023 · Here, we describe the engineering of a self-cyclising “ autocyclase ” protein, capable of performing a controllable unimolecular reaction for generation of cyclic biomolecules in high yield.

Oct 24, 2024 · Cyclization reactions are essential in synthesizing complex organic molecules, significantly impacting natural product synthesis and pharmaceutical development. These reactions form ring structures, altering the physical and chemical properties of compounds, which can enhance biological activity or stability.

1 day ago · The resulting Ru NCs in SBA-15 exhibit high catalytic performance for the cyclization of 2-methylpentanediamine to 3-methylpiperidine, initiating at 50 °C without byproducts. Importantly, deactivation of catalysts by ammonia (NH 3) was observed and conquered by transforming the reaction from a batch model to a continuous-flow model. Under ...