Other Click Reactions

In addition to the common six types of click reactions, several types of click reactions that are still in the research and development stage have also received widespread attention. Studies have shown that these click reactions have important applications in many fields, and deserve to be studied and explored in depth. Several examples of click reactions and their applications are briefly described below.

SPANC Click Reaction

Strain-promoted alkyne-nitrone cycloaddition (SPANC) click reaction is an important class of organic reaction that occurs between cycloalkynes and nitrones to produce isoxazolines. The reaction is characterized by fast reaction rates, low reagent concentrations, and stereo-electronic tunability. SPANC click reaction can be used in a variety of fields, from protein and cell surface labeling to materials science. The schematic diagram of SPANC click reaction between DBCO (a cycloalkyne) and nitrone is shown in scheme 1.

Scheme 1. The schematic diagram of SPANC click reaction
between DBCO (a cycloalkyne) and nitrone.

Thiol-Yne Click Reaction

Thiol-yne click reaction (also known as alkyne hydrothiolation) is a class of organic reaction between a thiol and an alkyne that produces an alkenyl sulfide. The reaction is one of the simplest and most atom-economic approaches to producing alkenyl sulfides. Generally, thiol-yne click reaction occurs in the presence of free radicals, strong acids, bases or transition metals. Studies have shown that the reaction is widely used in material synthesis, such as hydrogel synthesis and dendrimer synthesis. The schematic diagram of thiol-yne click reaction is shown in scheme 2.

Scheme 2. The schematic diagram of thiol-yne click reaction.

Spontaneous Amino-Yne Click Reaction

In 2017, a spontaneous amino-yne click reaction was first reported, which produced regio- and stereoregular products in excellent yields by simply mixing amines and alkynes at room temperature without any catalyst. In addition to the general advantages associated with click reactions, spontaneous amino-yne click reaction possesses extra merits, such as spontaneity of reaction, ubiquity of amines and cleavability of products with specific stimuli. Therefore, the reaction becomes a facile and efficient chemical tool for surface immobilization, drug delivery carrier design, hydrogel synthesis, and functional polymer synthesis. The schematic diagram of spontaneous amino-yne click reaction is shown in scheme 3.

Scheme 3. The schematic diagram of spontaneous amino-yne click reaction.

Photo-Triggered Click Reactions

Photo-triggered click reactions are based on the click reactions and are activated by photo. The reactions effectively combine the classical advantages of click reactions with the benefits of photochemical processes. For example, they can be activated at specific times and locations, resulting in powerful methods for chemical synthesis, bioorthogonal conjugation, and tailored material fabrication. At present, there are many photo-triggered click reactions that have been widely studied, including photo-triggered thiol-ene click reaction, photo-triggered Diels-Alder click reaction, photo-triggered strain-promoted azide-alkyne cycloaddition click reaction, etc.

What Can We Do?

As a leading customer-focused company, Alfa Chemistry has experienced experts and professional R & D laboratories. For many years, we have been focusing on reagent development and potential application exploration of SPANC, thiol-yne, spontaneous amino-yne and photo-triggered click reaction. If you have questions about these click reactions, please contact us. We will draw upon our wide range of advantages and high-quality products to create customized, scalable, efficient solutions for your research.