Date of Award
2011
Document Type
Thesis
Publication Status
Version of Record
Submission Date
October 2026
Abstract
We report here the development of very efficient aryl- and quinolinyl- sulfonate based leaving groups, termed Nucleophile Assisting Leaving Groups (NALGs), which substantially accelerate the rate of nucleophilic substitution reactions with metal halides. Detailed synthesis and kinetics study are described herein. Our synthesized NALGs have shown great reactivity towards poor nucleophiles and/or substrates traditionally considered too hindered to undergo nucleophilic attack. The abundant existence of halide, azide and amine in natural products demands new synthetic pathway. To fulfill this requirement, new mild stereoretentive halogenations (chlorination, bromination and iodination) reactions have also been developed for secondary cyclic alcohols using NALGs involving titanium (IV) reagents. The novel methodology can be extended to Azidation reactions as well with titanium (IV) azide, in which Ti (N3)4 is the first time being engaged in organic synthesis. Beased on the NALGs theory we discover the chlorosulfite can be a simplest NALG and applied as the intermediate in mild one-pot stereoretentive halogenations (chlorination and bromination) using titanium (IV) halides as catalysts or stoichiometric reagents. These reactions were found to be particularly efficient for cyclic alcohols. Finally, an efficient mild bromination and iodination reaction for primary and secondary alcohols with Grignard reagents is also reported. This reaction exhibits the generality with substrates with various leaving groups. The important features of this reaction are that, for the first time, bromide formation using Grignard reagents without the Cu (I) catalysts.
Extent
xiv, 135 p. : ill. (some col.)
Recommended Citation
Li, Songye., "Development and applications of nucleophile assisting leaving groups (NALGs) with Titanium (IV) and Grignard reagents" (2011). Electronic Theses and Dissertations 2010 - 2019. 245.
https://digitalcommons.fau.edu/etd_general_6/245
Identifier
FADT3183130
Comments
by Songye Li.|Thesis (Ph.D.)--Florida Atlantic University, 2011.|Includes bibliography.|Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.|by Songye Li.