Chemo- and Regioselectivity-Tunable Phosphination of Alkynes
Juan Ma1, Lili Wang1, Zheng Duan1
1College of Chemistry, Green Catalysis Center, International Phosphorus Laboratory, International Joint Research Laboratory for Functional Organophosphorus Materials of Henan Province, Zhengzhou University, Zhengzhou 450001, China.
Organic Letters
|February 14, 2022
Summary
This study introduces a new method for intramolecular phosphination of alkynes, controlling selectivity with simple additives. The research yields novel phosphacycles with potential applications in materials science.
Area of Science:
- Organic Chemistry
- Organophosphorus Chemistry
- Synthetic Methodology
Background:
- Intramolecular phosphination reactions are crucial for synthesizing phosphorus-containing heterocycles.
- Controlling chemo- and regioselectivity in these reactions remains a significant challenge.
- Development of efficient synthetic routes to functionalized phosphacycles is essential for exploring their properties.
Purpose of the Study:
- To develop a novel divergent intramolecular phosphination of alkynes.
- To achieve fine-tuning of chemo- and regioselectivity using simple additives like lithium bromide (LiBr) or water (H2O).
- To investigate the absorption and emission properties of the synthesized compounds.
Main Methods:
- Intramolecular phosphination reaction of alkynes.
- Use of LiBr or H2O as additives to control selectivity.
- Mechanistic studies involving control experiments and phosphorus-31 Nuclear Magnetic Resonance (31P NMR) spectroscopy.
- Spectroscopic analysis of absorption and emission properties.
Main Results:
- A divergent intramolecular phosphination of alkynes was successfully developed.
- Addition of LiBr led to the formation of 5-exo-dig phosphacycles.
- Addition of H2O resulted in the formation of 6-endo-dig phosphacycles, demonstrating high chemo- and regioselectivity.
- A plausible reaction mechanism was proposed and supported by experimental evidence.
- The absorption and emission characteristics of the resulting 1-phosphaphenalenes were investigated.
Conclusions:
- The developed method offers a versatile and selective approach to synthesizing diverse phosphacycles.
- The study provides insights into the mechanism of intramolecular phosphination.
- The synthesized 1-phosphaphenalenes exhibit interesting photophysical properties, suggesting potential for materials science applications.
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