Presentation Title

Mechanistic Challenges in Tranesterification During the Synthesis of Hypophosphite Esters

Faculty Mentor

Sylvine Deprele

Start Date

17-11-2018 2:15 PM

End Date

17-11-2018 2:30 PM

Location

C335

Session

Oral 3

Type of Presentation

Oral Talk

Subject Area

physical_mathematical_sciences

Abstract

One of the largest oil spills, the Deep Horizon Oil Spill, occurred in April 2010 and the more recent Santa Barbara Oil Spill in May 2015. Oil surfactants are a cleanup method that involve amphipathic organic molecules that form micelles and separate the large mass of oil into smaller droplets. This allows for bioremediation and our objective is to synthesize an environmentally friendly, phosphorus-based surfactant through a three-step synthesis process. Our three-step synthesis involves hypophosphite esters and a palladium-catalyzed hydrophosphinylation with bromoalkenes, followed by a reaction with a tertiary amine. During the first step, a transesterification mechanism occurs with the nucleophile attack of the desired alcohol chain to hypophosphous acid. Long chain alcohols are desired to produce the ideal characteristics of a surfactant, thus long chain alcohols were observed. To further gain a better insight of the diversity of long chains we looked at three different parameters that may have an effect on our product yield: solvent study, equivalence study and a time study. Our results showed that CH3CN at 4 equivalence produce the highest amount of product yield, compared to other solvents and equivalences. After further investigation it was discovered that our transesterification occurred within the first ten minutes instead of two hours which was previously anticipated. Alcohol classes were also examined, and as expected, primary alcohols produced higher yields due to less branching and steric hindrance than secondary and tertiary alcohols. After further examination of all of our parameters we discovered what parameters would yield higher products However, we also learned that it would be difficult to completely purify our samples. We will need to optimize our product yields before proceeding with our second synthesis step.

Summary of research results to be presented

Our results showed that CH3CN at 4 equivalence produce the highest amount of product yield, compared to other solvents and equivalences. After further investigation it was discovered that our transesterification occurred within the first ten minutes instead of two hours which was previously anticipated. Alcohol classes were also examined, and as expected, primary alcohols produced higher yields due to less branching and steric hindrance than secondary and tertiary alcohols.

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Nov 17th, 2:15 PM Nov 17th, 2:30 PM

Mechanistic Challenges in Tranesterification During the Synthesis of Hypophosphite Esters

C335

One of the largest oil spills, the Deep Horizon Oil Spill, occurred in April 2010 and the more recent Santa Barbara Oil Spill in May 2015. Oil surfactants are a cleanup method that involve amphipathic organic molecules that form micelles and separate the large mass of oil into smaller droplets. This allows for bioremediation and our objective is to synthesize an environmentally friendly, phosphorus-based surfactant through a three-step synthesis process. Our three-step synthesis involves hypophosphite esters and a palladium-catalyzed hydrophosphinylation with bromoalkenes, followed by a reaction with a tertiary amine. During the first step, a transesterification mechanism occurs with the nucleophile attack of the desired alcohol chain to hypophosphous acid. Long chain alcohols are desired to produce the ideal characteristics of a surfactant, thus long chain alcohols were observed. To further gain a better insight of the diversity of long chains we looked at three different parameters that may have an effect on our product yield: solvent study, equivalence study and a time study. Our results showed that CH3CN at 4 equivalence produce the highest amount of product yield, compared to other solvents and equivalences. After further investigation it was discovered that our transesterification occurred within the first ten minutes instead of two hours which was previously anticipated. Alcohol classes were also examined, and as expected, primary alcohols produced higher yields due to less branching and steric hindrance than secondary and tertiary alcohols. After further examination of all of our parameters we discovered what parameters would yield higher products However, we also learned that it would be difficult to completely purify our samples. We will need to optimize our product yields before proceeding with our second synthesis step.