131675-39-3Relevant academic research and scientific papers
Preparation of 3-substituted and 2,3-disubstituted-4,4,4-trifluoro-2-butenoic acids-Perkin condensation of activated aromatic ketones
Cserényi, Szabolcs,Felf?ldi, Károly,Forgo, Peter,Pálinkó, István
, p. 850 - 853 (2006)
The Perkin reaction of the activated aromatic ketones (2,2,2-trifluoroacetophenone and its 4′-phenyl-derivative) with various condensing agents (acetic anhydride, propionic anhydride, phenylacetic acid/acetic anhydride) gives the title compounds in good o
Phosphetane oxides as redox cycling catalysts in the catalytic wittig reaction at room temperature
Longwitz, Lars,Spannenberg, Anke,Werner, Thomas
, p. 9237 - 9244 (2019/10/08)
Recently, phosphorus redox cycling has gained significant importance for a number of transformations originally requiring the use of stoichiometric amounts of phosphorus reagents. While these methodologies have several benefits, high catalyst loadings (≥10 mol percent) and harsh reaction conditions (T ≥ 100 °C) often limit their versatility and applicability. Herein, we report differently substituted phosphetane oxides as efficient catalysts for the catalytic Wittig reaction. The phosphetane scaffold is easy to modify, and a number of catalysts can be obtained in a simple two-step synthesis. The activity in the Wittig reaction significantly surpasses previously reported phospholane-based catalysts and the reaction can be conducted with catalyst loadings as low as 1.0 mol percent even at room temperature. Furthermore, a Br?nsted acid additive is no longer required to achieve high yields at these mild conditions. A methyl-substituted phosphetane oxide was employed to synthesize 25 different alkenes with yields of up to 97percent. The methodology has a good functional group tolerance and the reaction can be performed starting with alkyl chlorides, bromides, or iodides. Additionally, it was possible to use poly(methylhydrosiloxane) as the terminal reductant in the catalytic Wittig reaction employing 2-MeTHF as a renewable solvent. The intermediates of the Wittig reaction were analyzed by 31P NMR spectroscopy, and in situ NMR experiments confirmed phosphane oxide as the resting state of the catalyst. Further kinetic investigations revealed a striking influence of the base on the rate of phosphane oxide reduction.
INHIBITORS OF BETA AMYLOID PRODUCTION
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Page/Page column 21-22, (2009/02/11)
Novel sulfonamide compounds useful in the treatment of conditions related to the production of beta-amyloid are described, as are routes to their preparation. The sulfonamide compounds are of the following structure, wherein R1-R3 are defined herein. Also provided are pharmaceutical compositions containing these compounds and/or prodrugs of these compounds and a physiologically compatible carrier. These compounds are specifically useful for inhibiting beta amyloid production, and treating Alzheimer's Disease, amyloid angiopathy, cerebral amyloid angiopathy, systemic amyloidosis, hereditary cerebral hemorrhage with amyloidosis of the Dutch type, inclusion body myositis, mild cognitive impairment (MCI) and Down's syndrome.
Remarkable reversal of stereoselectivity in Wittig-type olefinations of α-fluorinated alkyl aryl ketones
Eguchi,Aoyama,Kakinuma
, p. 5545 - 5546 (2007/10/02)
Remarkable reactivity and reversal of stereoselectivity in the Wittig-type olefinations of α-fluorinated alkyl aryl ketones were described. Stabilized Wittig and Horner-Emmons reagents with these ketones selectively afforded the olefinic products in the stereochemically opposite fashion to the non-fluorinated ketone cases. The Still's reagent further reversed the stereochemical outcome with the fluorinated ketones.
