Rhodium(I)‐Catalyzed Carboacylation/Aromatization Cascade Initiated by Regioselective C−C Activation of Benzocyclobutenones

Abstract

Described here is the first example of ar hodiumcatalyzedc arboacylation/aromatization cascade of aC = O bond by CÀCa ctivation. In this transformation, ar eactive rhodaindanone complex is regioselectively generated and adds across aC =Obond with subsequent elimination, thus providing au nique strategy to access am ultisubstituted benzofuran scaffold. Ad iverse range of benzofuran analogues were obtained in good yields.M echanistic studies show at ricyclic lactone was aviable intermediate.Application of this methodology to the total synthesis of C13-deOH-viniferifuran and C13-deOH-diptoindonesin Gw as achieved.

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.…”

“…Accordingly, the % inhibition was calculated according to the formula [1-(test substance A/solvent control A)×100. MTT on cells of increasing concentrations (1,2,4,8,16,32,64, and 128 µg / mL) of each test substance over a certain range to determine the IC 50 concentrations of test substances (concentration that inhibits the proliferation of 50% of cells in the medium) were prepared. Results were analyzed using a logarithmic function with the help of the Excel program over the logarithmic curve prepared from the absorbance values obtained after the test (Table 5).…”

“…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.…”

Hydrogen atom disorder in the crystal structure of o-phenylenediacetic acid

“…( Table 2). The search in CSD (Groom et al 2016) has shown that these values are from the ranges found for corresponding bond (Sun et al 2018). On the other hand, the mean values of 1.31(2) and 1.22(2) Å for C-O(H) and C=O bonds, resp., in carboxyl-syn structural fragment were reported (D'Ascenzo and Auffinger 2015).…”