Date of Award

5-31-2016

Document Type

Campus Access Thesis

Degree Name

Master of Science (MS)

Department

Chemistry/Organic Chemistry

First Advisor

Wei Zhang

Second Advisor

Daniel Dowling

Third Advisor

Jason Evans

Abstract

The synthesis of organofluorine molecules has become increasingly important in medicinal and agricultural chemistry because fluorinated molecules usually have unique chemical and biological properties. Fluorination can be combined with other chemicals in one-pot synthesis to save reaction time and energy, and to reduce the amount of waste by eliminating the intermediate purification step. The first project discussed in this thesis is the fluorination of β–keto carbonyl with SelectfluorTM followed by the Mannich reaction with anilines and benzaldehydes for the synthesis of α–fluoro and aminomethylated 1,3-dicarbonyl compounds.

Step-economic one-pot reactions, transition metal-free organocatalysis and catalyst recovery are green synthetic techniques. In the second project, one-pot Michael/aza-Henry/lactamization reaction promoted by a recyclable fluorous bifunctional cinchona alkaloid/thiourea organocatalyst was developed for asymmetric synthesis of fluorine-containing 2-piperidinones bearing four stereocenters in good yield and excellent stereoselectivity with up to 99% ee and 15:1 dr.

In the third project, a new one-pot quadruple cascade fluorination/Michael/Michael/aldol sequence for asymmetric synthesis of fluorine-containing polysubstituted cyclohexanes bearing six contiguous stereocenters was developed using the recyclable fluorous organocatalyst. The one-pot reactions gave polysubstituted cyclohexanes in 45-80% yields with up to 99% ee and 20:1 dr. The fluorous-organocatalyst was recovered from the reaction mixture in 94% yield and 98% purity by fluorous solid-phase extraction (F-SPE).

Comments

Free and open access to this Campus Access Thesis is made available to the UMass Boston community by ScholarWorks at UMass Boston. Those not on campus and those without a Healey Library (UMass Boston) barcode may gain access to this thesis through resources like Proquest Dissertations & Theses Global. If you have a Healey Library barcode and would like to download this work from off-campus, click on the "Off-Campus UMass Boston Users" link above.

Share

COinS