Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 1975 for “"Lewis"”.
-
Probing the Impact of Solvent on Lewis Acid Catalysis via Fluorescent Lewis Adducts
… have been developed to measure the strength of a Lewis acid. However, a major challenge for these measurements lies in the complexity that arises from variables, such as solvent and other fundamental interactions, as well as perturbations of Lewis acids as their reaction environment changes. …
-
Lewis Base Activation of Lewis Acids in Asymmetric Aldol Reactions of Silyl Ketene Acetals
The concept of Lewis base activation of Lewis acids has been effectively reduced to practice for catalysis in the chiral phosphoramide catalyzed/SiCl 4 promoted aldol reaction of silyl ketene acetals and silyl dienol ethers with aldehydes. The weakly acidic species, silicon tetrachloride (SiCl 4), …
-
Beiträge zur Chemie siliciumbasierter Lewis-Säuren
… Forschungsobjekte dar. Während monokationische Lewis-Säuren des Siliciums in der Literatur eingehend beschrieben wurden, beschäftigt sich die vorliegende Arbeit mit molekularen siliciumbasierten Polykationen und der Betrachtung ihrer Lewis-sauren Eigenschaften. Es wurde untersucht, inwiefern die …
-
Lewis acid catalysis in organic synthesis
"Gadolinium triflate (Gd(OTf)₃) was found to be a simple and efficient catalyst for the acetylation of alcohols and amines in both conventional organic solvents and as well as in room temperature ionic liquids (TRIL). Acetylation reactions using acetic anhydride as the reagent proceed in excellent …
-
Studies on Lewis Acid-Base Adducts
Made available in DSpace on 2014-12-10T23:01:16Z (GMT). No. of bitstreams: 1 7212280.pdf: 2128123 bytes, checksum: ac28befff6af3744a04c1efac9d7532f (MD5) Previous issue date: 1971
-
Gas Phase Lewis Acid-Base Interactions
Made available in DSpace on 2014-12-09T17:35:07Z (GMT). No. of bitstreams: 1 6503665.pdf: 4735633 bytes, checksum: 52109a08d7e92e8f90ec7b5e4956af0d (MD5) Previous issue date: 1964
-
From isolation to incorporation : medical-theological imagery in the work of T.S. Eliot, C.S. Lewis, and Gwyneth Lewis.
… Christian authors: T.S. Eliot (1888-1965), C.S. Lewis (1898-1963) and Gwyneth Lewis (b.1959). Through a detailed analysis of each author's medical-theological imagery, I argue that all three authors interweave medical and theological imagery to comment on the relationship between bodies and …
-
Studies in Asymmetric Catalysis: Lewis Base catalyzed/Lewis Acid Mediated Aldol Reactions of Ketone- and Amide Derived Nucleophiles
Additionally, the use of the silicon tetrachloride---chiral phosphoramide system has proven a competent catalyst for highly selective vinylogous aldol reactions between dienolates derived from a variety of alpha,beta-unsaturated carbonyl compounds to aldehydes. These reactions provided high levels …
-
CHIRAL LEWIS BASES ACTIVATION OF TRICHLOROSILYL DERIVATIVES
The design and synthesis of new chiral Lewis bases is a field of extraordinary activity. Among the different classes of Lewis Bases that are able to promote stereoselective reactions, we have studied three class of compounds: phosphoramides, phosphoramidates and phosphine oxides. These compounds, …
-
Empty admiration: Robert Lewis Dabney’s expository homiletic
Russell St. John, “Empty Admiration: Robert Lewis Dabney’s Expository Homiletic,” Doctor of Philosophy, Middlesex University/London School of Theology, 2018. ----- This thesis argues that while American homiletician Robert Lewis Dabney (1820-1898) crafted a robust expository homiletical theory, his …
-
Wyndham Lewis and his readers: 1911-1931
… of the painting and writings of Wyndham Lewis from his first exhibitions in 1911 through to the publication of Hitler in 1931, and is based on a new checklist of criticism and reviews. The study shows that Lewis monitored his reputation with great care, and that many of his decisions with …
-
Idealism in the novels of Sinclair Lewis.
Throughout his literary career Sinclair Lewis displayed idealism in his novels, though, with the exception of Arrowsmith, he became more realistic as he grew older. To trace his idealism, one may divide his literary career into three periods suggested by Geoffrey Moore in his essay "Sinclair Lewis: …
-
Lewis base catalyzed enantioselective oxysulfenylation of alkenes
The Lewis base activation of Lewis acids has been harnessed in the development of an enantioselective oxysulfenylation reaction for unactivated alkenes. The weak Lewis acid N-(phenylthio)-phthalimide can be activated in the presence of a moderate Brønsted acid and chiral Lewis base donors. The …
-
Lewis base catalyzed enantioselective sulfenoamination of alkenes
The concept of Lewis base activation of Lewis acid has been successfully applied to the enantioselective sulfenoamination of olefins. The unreactive, achiral Lewis acidic sulfenylating agent, N-arylthiophthalimide, is activated by the coordination of a chiral Lewis base, binaphthyl-derived …
-
Calorimetric Investigations of Lewis Acid-Base Interactions
Made available in DSpace on 2014-12-10T23:01:56Z (GMT). No. of bitstreams: 1 7500316.pdf: 3856228 bytes, checksum: 8a099174383142d44c149312c85aecba (MD5) Previous issue date: 1974
-
The Lewis Acid Properties of Titanium-Tetrafluoride
Made available in DSpace on 2014-12-05T19:37:13Z (GMT). No. of bitstreams: 1 6000156.pdf: 3320366 bytes, checksum: 789b42765e2f9190645b95d900ee555a (MD5) Previous issue date: 1959
-
Frustrated Lewis Pair Reactivity of Phosphino-Phosphenium Cations
The field of “frustrated Lewis pairs” (FLPs) broke the century-old paradigm that activation and cleavage of small molecules such as H2 belonged to the realm of transition metal chemistry. Since Stephan and co-workers’ seminal report on reversible H2 activation using a main-group phosphinoborane, the …
-
A Lewis Acidic Stroll Through the p-Block
Since the inception of frustrated Lewis pair (FLP) chemistry more than a decade ago, the development of an assortment of main group Lewis acids in the literature has contributed to the enrichment and diversification of FLP reactivity to achieve transition metal-like chemistry. While most of the …
Page 1 of 99