N-Fluoro-3-cyclohexyl-3-methyl-2,3- dihydrobenzo[1,2-d]isothiazole 1,1-Dioxide:  An Efficient Agent for Electrophilic Asymmetric Fluorination of Enolates

N-Fluoro-(3,5-di-tert-butyl-4-methoxy)benzenesulfonimide (NFBSI): A sterically demanding electrophilic fluorinating reagent for enantioselective fluorination

“…Synthesis of fluorinating reagent, NFBSI (1). H. Yasui et al / Journal of Fluorine Chemistry 132 (2011) 222-225 223values [4,12]. We first attempted the enantioselective fluorination of silylenol ether of 2-benzyl-1-indanone 6a in the presence of a catalytic amount of quinine-1-naphtoate with an excess amount of K 2 CO 3 with NFBSI or NFSI in MeCN (Scheme 2a).…”

“…Selection of cinchona alkaloids for each reaction was based on our previous observations for the same fluorination reaction [4] in which the fluorination products had been isolated via column chromatography on silica-gel and identified by comparison of their MS-and NMR-spectral data as well as HPLC analysis with literature values [4,12]. We first attempted the enantioselective fluorination of silylenol ether of 2-benzyl-1-indanone 6a in the presence of a catalytic amount of quinine-1-naphtoate with an excess amount of K 2 CO 3 with NFBSI or NFSI in MeCN (Scheme 2a).…”

Development of the titanium–TADDOLate-catalyzed asymmetric fluorination of β-ketoesters

“…Initially, chiral auxiliary approaches and diastereoselective reactions were developed, before Differding and Lang found the first stoichiometric asymmetric fluorination of β-ketoester enolates with a chiral N–F ( N -fluoroamine) reagent in 1988 [21]. Later work by Davis [22–23], Takeuchi [24] and their respective coworkers extended this chemistry, while Haufe and coworkers were able to open meso -epoxides asymmetrically with HF equivalents and chiral chromium–salen complexes [25–26]. In the year 2000, two conceptually different applications of Banks’ electrophilic fluorinating reagent F–TEDA (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate); TEDA = triethylenediamine) [27–29] marked some important discoveries: First, a new generation of highly enantioselective chiral fluorinating reagents, derived by fluorine transfer [30] from F–TEDA to the quinuclidine portion of cinchona-alkaloids, was introduced by the groups of Cahard [31–33] and Shibata [34–35].…”

Galvanostatic and potentiostatic fluorination of 2-indanone, 1-indanone and 1,3-indandione in Et3N · 4HF medium. Adsorption effects on yield and product selectivity

“…It is also well known that a-fluoro carbonyl compounds can substantially improve the biological activity of the parent drug molecule [2,3]. There are only few reports on the halogenation of indanones including fluorination either by chemical or electrochemical methods in the literature [1,4]. Substituted 1,3-indandione [1] as well as substituted 1-indanone [4] have been chemically fluorinated using active organic fluorinating agents.…”

“…There are only few reports on the halogenation of indanones including fluorination either by chemical or electrochemical methods in the literature [1,4]. Substituted 1,3-indandione [1] as well as substituted 1-indanone [4] have been chemically fluorinated using active organic fluorinating agents. 1-Indanone and 2-indanone have also been chemically fluorinated using inorganic fluorinating agents, namely XeF 2 and CsSO 4 F [5].…”