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Ellman Mary — Thinking about Women
No full textH. J. Ellman Mary — Thinking about Women. In: Population, 25ᵉ année, n°2, 1970. p. 453
Ellman Mary — Thinking about Women
No full textH. J. Ellman Mary — Thinking about Women. In: Population, 25ᵉ année, n°2, 1970. p. 453
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New Methods for the Synthesis of alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl Imines AND The Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide Organocatalysts
No full textAbstractNew Methods for the Synthesis of alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl IminesANDThe Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide OrganocatalystsbyMelissa Ann HerbageDoctor of Philosophy in ChemistryUniversity of California, BerkeleyProfessor Jonathan A. Ellman, ChairChapter 1. Methods for the synthesis of alpha-amino acid derivatives prepared from N-tert-butanesulfinyl imines are reviewed.Chapter 2. The rhodium-catalyzed addition of arylboronic acids to N-tert-butanesulfinyl imino esters is described. This chemistry is compatible with a variety of electronically and sterically diverse arylboronic acids providing the N-tert-butanesulfinyl protected alpha-arylglycine products in good yields and high diastereoselectivities. In addition, the utility of this method is demonstrated by subjecting the enantiomerically enriched N-tert-butanesulfinyl protected products to selective synthetic manipulations with little to no racemization. The synthesis of an N-tert-butanesulfinyl isatin imine and its use in the rhodium-catalyzed addition of arylboronic acids reaction is also described. Chapter 3. The copper-catalyzed addition of bis(pinacolato)diboron to N-tert-butanesulfinyl imines is described. This chemistry is amenable to a variety of alkyl and aryl N-tert-butanesulfinyl imines and provides rapid access to use of a number of chiral alpha-amino boronate esters, a biologically relevant scaffold that is difficult to access by other means. The utility of this methodology was demonstrated by the efficient synthesis of bortezomib (Velcade®), the first FDA approved proteasome inhibitor drug. The further functionalization of the alpha-amino boronate products is also described. This includes the homologation of the alpha-amino boronate ester products as well as the conversion of the boronate ester to the potassium trifluoroborate salt. The application of this methodology for the enantioselective synthesis of alpha-amino boronate esters is also addressed. Chapter 4. The synthesis of new N-tert-butanesulfinyl amide organocatalysts and their application to the intermolecular aldol reaction is described. A number of catalysts were prepared in one step from commercially available amino acid precursors and were tested for their activity in the intermolecular aldol reaction. However, preliminary results indicate that the primary amine catalysts are not competitive with other amino acid derived catalysts reported in the literature. Further optimization is necessary to fully evaluate the potential for this new class of catalysts
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral <i>N‑tert</i>-Butanesulfinyl Imines
No full textA highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral <i>N‑tert</i>-Butanesulfinyl Imines
No full textA highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral <i>N‑tert</i>-Butanesulfinyl Imines
No full textA highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral <i>N‑tert</i>-Butanesulfinyl Imines
No full textA highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral <i>N‑tert</i>-Butanesulfinyl Imines
No full textA highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral <i>N‑tert</i>-Butanesulfinyl Imines
No full textA highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
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