Epoxidation with dioxiranes derived from 2-fluoro-2-substituted-1-tetralones and -1-indanones
摘要:
Homochiral 2-fluoro-2-substituted-1-tetralones (10a, 10b, 13) and ethyl 2-fluoro-1-indanone-2-carboxylate (16) have been isolated. The dioxirane derivatives of these ketones have been prepared in situ, and have been shown to epoxidise alkenes but not enantioselectively. The dioxirane derivative of methyl 2,5,7-trifluoro-1-indanone-2-carboxylate (18) has been shown to be comparatively efficient in epoxidation.
design, synthesis, and application of de novo chiral fluorinating agents as analogues of popular N-fluorodibenzenesulfonimide (NFSI). The fluorination step by means of elemental fluorine is presented. Enantioselectivefluorination is demonstrated in cyclic β-keto esters and in the synthesis of BMS-204352 (up to 86 % ee). Oxidative aminofluorination is also examined.
Self‐Sustaining Fluorination of Active Methylene Compounds and High‐Yielding Fluorination of Highly Basic Aryl and Alkenyl Lithium Species with a Sterically Hindered
<i>N</i>
‐Fluorosulfonamide Reagent
作者:Yuhao Yang、Gerald B. Hammond、Teruo Umemoto
DOI:10.1002/anie.202211688
日期:2022.10.24
By developing a sterically hindered fluorinating agent, N-fluoro-N-(tert-butyl)-tert-butanesulfonamide (NFBB), we discovered a conceptually novel base-catalyzed, self-sustaining fluorination of active methylene compounds and achieved an unprecedented high-yield fluorination of highly basic (hetero)aryl and alkenyl lithium species.
N-Fluoro-3-ethyl-3-methyl-1,1-dioxo-2,3-dihydro-1H-1λ6-benzo[e]1,2-thiazin-4-one, a new and efficient agent for electrophilic fluorination of carbanions
作者:Yoshio Takeuchi、Zhaopeng Liu、Emiko Suzuki、Norio Shibata、Kenneth L Kirk
DOI:10.1016/s0022-1139(99)00028-7
日期:1999.7
N-Fluoro-3-ethyl-3-methyl-1,1-dioxo-2,3-dihydro-1H-1 lambda(6)-benzo[e]1,2-thiazin-4-one (1) was prepared in good yield by fluorination of the corresponding sultam (3) with FClO3. The sultam (3) was prepared from saccharin (2) in 3 steps. The N-fluorosultam (1), a very stable crystalline solid, was found to fluorinate carbanions readily in good to excellent yields. (C) 1999 Elsevier Science S.A. All rights reserved.