The key difference between Heck Stile and Suzuki reaction is that Heck reaction involves the coupling of an unsaturated halide with an alkene whereas, Stile reaction involves the coupling of an organotin compound with a halide compound. Meanwhile, Suzuki reaction involves the coupling of boronic acid with an organohalide compound.
Heck reaction, Stile reaction and Suzuki reaction are three types of organic reactions which are categorized as coupling reactions.
CONTENTS
1. Overview and Key Difference
2. What is Heck Reaction
3. What is Stile Reaction
4. What is Suzuki Reaction
5. Side by Side Comparison – Heck Stile vs Suzuki Reaction in Tabular Form
6. Summary
What is Heck Reaction?
Heck reaction is a type of organic coupling reaction which involves the coupling of an unsaturated halide with an alkene. This reaction was named after Richard F. Heck. He was also awarded the Nobel prize in 2010 along with two other scientists for this development. It occurs in the presence of a base and a palladium catalyst. This reaction forms a substituted alkene as the final product. Therefore, we can consider it as a way of substituting two alkene compounds.
Figure 01: Heck Reaction
The Heck reaction can be catalyzed using palladium salts and complexes. Some examples for these catalysts include tetrakis(triphenylphosphine)palladium(0), palladium chloride, and palladium(II) acetate.
When considering the reaction mechanism of the Heck reaction, it involves organopalladium intermediates. The major steps of Heck reaction include oxidative addition, insertion of the alkene into the palladium-carbon bond in a syn addition, beta hydride elimination reaction and regeneration of the catalyst.
What is Stile Reaction?
Stile reaction is a type of organic coupling reaction which involves the coupling of the organotin compound with a halide compound. This reaction involves organic electrophiles that provide the other coupling partner.
Figure 02: Mechanism of Stile Reaction
When considering the mechanism of the Stile reaction, there is a catalytic cycle which involves oxidative addition of a halide to a palladium catalyst, followed by reductive elimination, yielding the coupled product and finally regenerating catalyst.
Moreover, there are different applications of Stile reaction, including the synthesis of a variety of polymers. It is also used in organic syntheses, specifically in the synthesis of natural products.
What is Suzuki Reaction?
Suzuki reaction is a type of organic reaction in which the coupling of boronic acid with an organohalide compound occurs. The catalyst for this coupling reaction is palladium (0) complex. This reaction was named after Akira Suzuki in 1979. This reaction is also named as Suzuki coupling. The reaction has various applications, including the synthesis of polyolefins, styrenes, and substituted biphenyls.
Figure 03: Mechanism of Suzuki Reaction
The reaction mechanism of Suzuki reaction involves several steps, including the oxidative addition of palladium to the halide forming the organopalladium species, followed by the formation of an intermediate via transmetalation along with the boronate complex; finally, reductive elimination occurs, producing the desired product and restoring the original palladium catalyst. This final step completes the catalytic cycle. Applications of Suzuki reaction includes synthesis of intermediates for pharmaceuticals or fine chemicals.
What is the Difference Between Heck Stile and Suzuki Reaction?
Heck, Stile and Suzuki reaction are three types of organic coupling reactions. The key difference between Heck Stile and Suzuki reaction is that the Heck reaction involves the coupling of an unsaturated halide with an alkene, and the Stile reaction involves the coupling of an organotin compound with a halide compound, whereas the Suzuki reaction involves the coupling of boronic acid with an organohalide compound.
Below is a tabulation of the differences between Heck Stile and Suzuki reaction for side-by-side comparison.
Summary – Heck Stile vs Suzuki Reaction
Heck reaction, Stile reaction and Suzuki reaction are organic chemical reactions that we can categorize as coupling reactions. The key difference between Heck Stile and Suzuki reaction is that Heck reaction involves the coupling of an unsaturated halide with an alkene and the Stile reaction involves the coupling of an organotin compound with a halide compound, whereas Suzuki reaction involves the coupling of boronic acid with an organohalide compound.
Reference:
1. “Heck Reaction.” Chemistry LibreTexts, Libretexts, 15 Aug. 2020, Available here.
Image Courtesy:
1. “Heck Reaction Scheme” By ~K – Own work. High-resolution PNG; ChemDraw / The GIMP. (Public Domain) via Commons Wikimedia
2. “Catalytic cycle of the Stille reaction” By Crshugrue – Own work, modified from Kurti, L.; Czako, B. Strategic Applications of Named Reactions in Organic Synthesis; Elsevier: Burlington, 2005. (CC BY-SA 3.0) via Commons Wikimedia
1. “Suzuki Coupling Full Mechanism 2” By Organic Chemist 19 – Own work (CC BY-SA 3.0) via Commons Wikimedia
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