Magnesium Aldimines Prepared by Addition of Organomagnesium Halides to 2,4,6‐Trichlorophenyl Isocyanide: Synthesis of 1,2‐Dicarbonyl Derivatives

Abstract

The selectivea ddition of organomagnesium reagents to 2,4,6-trichlorophenyl isocyanide leading to magnesiated aldimines is reported. These aldimines reactw ith Weinreb amides, ketones, or carbonates to provide the corresponding carbonyl derivativesa fter acidic cleavage. This allows for an efficient synthesis of 1,2-dicarbonyl compoundsa nd a-hydroxy ketones.

Synthesis of hydroxy benzoin/benzil analogs and investigation of their antioxidant, antimicrobial, enzyme inhibition, and cytotoxic activities

“…After chromatographic purification, compounds 1-7 (39-68% yields, respectively) were obtained as a racemic mixture (Figure) [4,. Hydroxy benzil compounds (8)(9)(10)(11)(12)(13)(14) were synthesized from hydroxy benzoins' oxidation (1-7) [72][73][74] with conc. nitric acid, PCC, and Fehling reagent.…”

“…The reaction of hydroxy benzoins (1-7) and benzils (8)(9)(10)(11)(12)(13)(14) with TABG then hydrolysis of acetyl group yielded benzoin-D-glucosides (15)(16)(17)(18)(19)(20) and benzil-D-glucosides (22)(23)(24)(25), respectively [21][22]. Observation of the anomeric proton coupling constant value around J = 7-8 Hz in the 1 H NMR spectrum of the synthesized benzoin/benzil-O-β-D-glucosides shows that the D-glucose unit was in the β form.…”

“…Acetone was evaporated, then water (30 mL) was added to the flask, extracted with ethyl acetate (3×30 mL) to give crude mixture then compounds 8-15 were purified with repeated VLC (Silica gel 230-400 mesh) using the increasing polarity of n-hexane, chloroform, ethyl acetate, and methanol solvent mixtures, and the fractions were checked by TLC (Figure). The synthesis of compounds 8 [23], 9 [9], 11 [44], and 15 [commercial product] had been mentioned in the literature.…”

“…The benzoin condensation reaction is an important type of C-C bond formation reaction and is widely used to synthesize natural compounds and analogs. Symmetric and asymmetric benzoin derivative synthesis using different catalysts in benzoin condensation have been studied under milder reaction conditions [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. However, the condensation of two different benzaldehydes may have a widely different character; only the more stable form of the isomeric mixed benzoins could be isolable in excess.…”

“…The significance of benzoin/benzil and carbohydrate-based agents caught our attention for the synthesis of benzoin/ benzil-O-β-D-glucosides, and we decided to study their pharmacological activities. Due to the biological activities' evaluation, we wish to report the synthesis of hydroxy benzoins (1-7) from hydroxy benzaldehydes, hydroxy benzils (8)(9)(10)(11)(12)(13)(14) from the oxidation of benzoins (1-7), and benzoin/benzil-O-β-D-glucosides (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) from the glycosylation of hydroxy benzoins/benzils (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Then, their antioxidant, antimicrobial, enzyme inhibitions, and cytotoxic activity investigations were reported.…”