Development of a New Reaction for One-Pot Synthesis of Diazo Compounds from Azides ~Paving a New Path for the Synthesis of Nitrogen-Containing Heterocyclic Compounds Useful in Drug Development~
A research group at Tokyo University of Science has developed a new reaction for the safer and more efficient synthesis of diazoesters, which are essential for drug development. By simultaneously advancing Michael addition and N-N bond cleavage via a stable phosphazide intermediate formed from azide compounds and phosphines, this method establishes a foundational technology for the synthesis of various nitrogen-containing heterocyclic compounds.
📋 Article Processing Timeline
- 📰 Published: May 1, 2026 at 19:00
- 🔍 Collected: May 1, 2026 at 10:31
- 🤖 AI Analyzed: May 1, 2026 at 12:07 (1h 35m after Collected)
## Research Summary and Key Points
Diazoesters are important compounds widely used in the synthesis of pharmaceuticals and functional molecules, but a more practical and safer manufacturing method has been sought.
We have developed a new reaction that allows for the one-pot synthesis of useful diazoesters under mild conditions, through a phosphazide intermediate generated from 2-azidoacrylates and phosphines, where Michael addition and N-N bond cleavage proceed simultaneously.
This method can be applied to nucleophiles such as thiols and amines, and the resulting diazoesters can be converted into enaminones, indoles, pyrazoles, etc., making it expected to be applied as a foundational technology supporting pharmaceutical synthesis.
## Research Overview
A research group consisting of Professor Yu Yoshida of the Department of Life Science and Engineering, Faculty of Advanced Engineering, Tokyo University of Science, Mr. Yuki Mano (2nd year Master's student, 2026 academic year), Mr. Takahiro Yasuda (1st year Doctoral student, 2026 academic year), and Mr. Masahisa Orimoto (completed Master's degree, 2023 academic year) from the Graduate School of Advanced Engineering, Department of Life Science and Engineering, Tokyo University of Science, has developed a new synthetic reaction to obtain useful diazoesters (*1) from 2-azidoacrylates. This reaction is characterized by the simultaneous progression of Michael addition (*5) and N-N bond cleavage, utilizing a relatively stable intermediate called phosphazide (*4), which is generated from azide compounds (*2) and phosphines (*3).
Diazoesters are important compounds widely used in the synthesis of pharmaceuticals, functional molecules, and the like. Conventionally, their synthesis involved hazardous diazomethane, and a more practical and safer manufacturing method was desired. The research group tackled this challenge by exploring new uses for the azido group, based on their unique method of utilizing azide compounds as stable phosphazides.
In this study, it was clarified that various diazoesters can be synthesized under mild conditions using thiols, amines, and other reagents. Furthermore, it was demonstrated that the obtained compounds can be converted into enaminones, indoles, and pyrazoles. This research is expected to serve as a foundational technology supporting the synthesis of pharmaceuticals and functional molecules.
These research results were published online in the international academic journal "Angewandte Chemie International Edition" on April 20, 2026.
Figure: Michael addition reaction involving azido-diazo (N3-to-N2) conversion found in this research.
## Research Background
Diazoacetic acid ester derivatives are important compounds for synthesizing various nitrogen-containing compounds. They have been reported to be used in dipole cycloaddition reactions, reduction reactions, and reactions using transition metal catalysts, and have been utilized in a wide range of organic synthesis.
On the other hand, the synthesis of these compounds involves processes that use hazardous reagents such as diazomethane, and the development of more practical and safer manufacturing methods has been a challenge. Although methods for converting azide compounds to diazo compounds have already been reported, methods for developing new reaction forms by utilizing stable intermediates have not been sufficiently explored.
Against this background, this research group aimed to find new uses for the azido group, based on their unique method of utilizing azide compounds as stable phosphazides. In particular, they embarked on this research with the idea that utilizing the properties of stable phosphazide intermediates generated from 2-azidoacrylates could lead to a new reaction design for obtaining useful diazoesters under more practical conditions.
## Details of Research Results
The research investigated a reaction in which thiols were added after forming a phosphazide intermediate from 2-azidoacrylates using Amphos, a type of phosphine. Contrary to initial expectations, it was found that diazoesters were formed accompanied by N-N bond cleavage. That is, it became clear that a new molecular transformation occurs, where Michael addition and azido-to-diazo conversion proceed sequentially via a stable phosphazide intermediate. Since 2-azidoacrylates can be prepared in two steps from the corresponding acrylates, this discovery is a result that leads to a new method for easily obtaining useful diazoacetic acid ester derivatives.
Bulky and electron-rich phosphines are suitable for this reaction, with Amphos being the most effective. Regarding the substrate scope, it was confirmed that in addition to thiols such as primary and secondary alkyl thiols, aromatic thiols, and protected cysteine derivatives, linear and cyclic secondary amines can also be used. It was also shown that it can be applied to substrates with various functional groups such as bromo groups, hydroxyl groups, and esters, and can be developed for the synthesis of fluoxetine derivatives. Furthermore, it has been synthesized on a 10 mmol scale, demonstrating the practicality of this method.
Diazoesters are important compounds widely used in the synthesis of pharmaceuticals and functional molecules, but a more practical and safer manufacturing method has been sought.
We have developed a new reaction that allows for the one-pot synthesis of useful diazoesters under mild conditions, through a phosphazide intermediate generated from 2-azidoacrylates and phosphines, where Michael addition and N-N bond cleavage proceed simultaneously.
This method can be applied to nucleophiles such as thiols and amines, and the resulting diazoesters can be converted into enaminones, indoles, pyrazoles, etc., making it expected to be applied as a foundational technology supporting pharmaceutical synthesis.
## Research Overview
A research group consisting of Professor Yu Yoshida of the Department of Life Science and Engineering, Faculty of Advanced Engineering, Tokyo University of Science, Mr. Yuki Mano (2nd year Master's student, 2026 academic year), Mr. Takahiro Yasuda (1st year Doctoral student, 2026 academic year), and Mr. Masahisa Orimoto (completed Master's degree, 2023 academic year) from the Graduate School of Advanced Engineering, Department of Life Science and Engineering, Tokyo University of Science, has developed a new synthetic reaction to obtain useful diazoesters (*1) from 2-azidoacrylates. This reaction is characterized by the simultaneous progression of Michael addition (*5) and N-N bond cleavage, utilizing a relatively stable intermediate called phosphazide (*4), which is generated from azide compounds (*2) and phosphines (*3).
Diazoesters are important compounds widely used in the synthesis of pharmaceuticals, functional molecules, and the like. Conventionally, their synthesis involved hazardous diazomethane, and a more practical and safer manufacturing method was desired. The research group tackled this challenge by exploring new uses for the azido group, based on their unique method of utilizing azide compounds as stable phosphazides.
In this study, it was clarified that various diazoesters can be synthesized under mild conditions using thiols, amines, and other reagents. Furthermore, it was demonstrated that the obtained compounds can be converted into enaminones, indoles, and pyrazoles. This research is expected to serve as a foundational technology supporting the synthesis of pharmaceuticals and functional molecules.
These research results were published online in the international academic journal "Angewandte Chemie International Edition" on April 20, 2026.
Figure: Michael addition reaction involving azido-diazo (N3-to-N2) conversion found in this research.
## Research Background
Diazoacetic acid ester derivatives are important compounds for synthesizing various nitrogen-containing compounds. They have been reported to be used in dipole cycloaddition reactions, reduction reactions, and reactions using transition metal catalysts, and have been utilized in a wide range of organic synthesis.
On the other hand, the synthesis of these compounds involves processes that use hazardous reagents such as diazomethane, and the development of more practical and safer manufacturing methods has been a challenge. Although methods for converting azide compounds to diazo compounds have already been reported, methods for developing new reaction forms by utilizing stable intermediates have not been sufficiently explored.
Against this background, this research group aimed to find new uses for the azido group, based on their unique method of utilizing azide compounds as stable phosphazides. In particular, they embarked on this research with the idea that utilizing the properties of stable phosphazide intermediates generated from 2-azidoacrylates could lead to a new reaction design for obtaining useful diazoesters under more practical conditions.
## Details of Research Results
The research investigated a reaction in which thiols were added after forming a phosphazide intermediate from 2-azidoacrylates using Amphos, a type of phosphine. Contrary to initial expectations, it was found that diazoesters were formed accompanied by N-N bond cleavage. That is, it became clear that a new molecular transformation occurs, where Michael addition and azido-to-diazo conversion proceed sequentially via a stable phosphazide intermediate. Since 2-azidoacrylates can be prepared in two steps from the corresponding acrylates, this discovery is a result that leads to a new method for easily obtaining useful diazoacetic acid ester derivatives.
Bulky and electron-rich phosphines are suitable for this reaction, with Amphos being the most effective. Regarding the substrate scope, it was confirmed that in addition to thiols such as primary and secondary alkyl thiols, aromatic thiols, and protected cysteine derivatives, linear and cyclic secondary amines can also be used. It was also shown that it can be applied to substrates with various functional groups such as bromo groups, hydroxyl groups, and esters, and can be developed for the synthesis of fluoxetine derivatives. Furthermore, it has been synthesized on a 10 mmol scale, demonstrating the practicality of this method.