2026-09-22T11:07:39Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/84439 2023-07-11 col_2142_5131 col_2142_14789 com_2142_5130 com_2142_14788 com_2142_8903

Embargo set by: Seth Robbins for item 85720 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Denmark, Scott E. Su, Xiping 2015-09-25T22:14:30Z 2015-09-25T22:14:30Z 10000-01-01 1999 1999 A dramatic rate acceleration by phosphoramides is observed for the addition of the trichlorosilyl enolate, 1-trichlorosiloxycyclohexene, to aldehydes. Both the enantio- and diastereoselectivities of the reaction vary dramatically with the structure of phosphoramides. It is believed that the reaction proceeds through a six-membered ring closed transition state with the ionization of a chloride from the trichlorosilyl enolate with either one or two phosphoramide molecules binding to the silicon. A nonlinear effect with enantio enriched phosphoramides supports the hypothesis. Studies by X-ray crystallography of phosphoramide-Lewis acid complexes revealed detailed structural information about the binding of chiral phosphoramides to Lewis acids. Transition state models are proposed based on the conformational preference of chiral phosphoramides in binding to Lewis acids. Made available in DSpace on 2015-09-25T22:14:30Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9921742.pdf: 15075550 bytes, checksum: 8197588e76ca72109bbf191db3b95538 (MD5) Previous issue date: 1999 Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 357 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1999. http://hdl.handle.net/2142/84439 (MiAaPQ)AAI9921742 eng Chemistry, Organic Lewis Base-Catalyzed Enantioselective Allylation and Aldol Addition Reactions text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.