Synthesis of α, β-Substituted Alkenylphosphonates from α-Phosphonovinyl Triflates: I) Palladium Catalyzed Suzuki-Miyaura Cross-coupling with Aryl Boronic Acids II) Palladium Catalyzed Reduction

<p>Alkenylphosphonates (vinylphosphonates) are important targets for R & D because they have interesting chemical, biological and pharmacological properties. Vinylphosphonates are used in synthesis, polymer applications, and have demonstrated potential as anticancer and antimicrobial agents.</p> <p>Vinyl triflates are useful in organic synthesis and are referred to as pseudo-halides because they react in a manner similar to halides. Vinyl triflates have a broad range of synthetic utility because they undergo nucleophilic substitutions and transition metal-mediated reactions. There is a growing interest in using α-phosphonovinyl pseudo-halides in transition metal-mediated cross-coupling reactions as a means to synthesize α, β-substituted alkenylphosphonates. Over the past three years, our group has developed a reliable synthesis of novel α-phosphonovinyl triflates from α-ketophosphonates and has been exploring the reactivity of these vinyl triflates.</p> <p>Part I of this thesis describes the synthesis of 1-aryl-1-alkenyl phosphonates through an environmentally friendly Pd-mediated Suzuki reaction of α-phosphonovinyl triflates and aryl boronic acids. The cross-coupling reactions were completed using simple reaction conditions, green solvents (isopropyl alcohol/H₂O), a heterogeneous catalyst with a very low mole loading (0.007%), and a benign base. The 1-aryl-1-alkenyl phosphonates were prepared in 72-98% yield after purification. Part II of this thesis describes the Pd-mediated reduction of α-phosphonovinyl triflates in the presence of formic acid as a new method to prepare β-substituted alkenylphosphonates in 64-90% yield.</p>

Name thesis:degree_name

Master of Science in Chemical Sciences (MSCB)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2017

Author dc:creator

• Mensah, Ronald laryea

Contributors dc:contributor

• Christopher W. Alexander
• Daniela Tapu
• Michael Van Dyke

• vinylphosphonate
• Suzuki-Miyaura
• vinyl triflate
• alkenylphosphonate
• alpha-phosphonovinyl triflate
• Montmorillonite clay
• Bis(triphenylphosphine)palladium(II) dichloride
• cross-coupling
• palladium
• reduction
• Chemistry
• Organic Chemistry

Repository record dc:identifier

https://digitalcommons.kennesaw.edu/mscs_etd/16

OAI identifier oai:identifier

oai:digitalcommons.kennesaw.edu:mscs_etd-1016