WebLog Journal of Molecular and Cellular Biology

The first theoretical investigation on NiF2 /picolinic acid-catalyzed chemoselective cou-pling− cyclization of 2-iodobenzamide and malonate was provided by our DFT calculation. First in Ni(I)/ Ni(III) catalytic cycle, NiF2 and PicA are converted to L2 Ni(II) complex together with leaving of first HF molecule. Then malonate anion is generated from dimethyl malonate after removal of second HF molecule. The deprotona-tion of malonate gives enolate as single-electron reductant furnishing Ni(I)…

The first theoretical investigation on DABCO-mediated aza-Michael reaction of sulfonyli minoindoline and α,β-unsaturated aldehyde was provided by our DFT calculation. First, 2-aminotosyl indole is given in equilibrium with 2-sulfonamidoindoline via deprotonation with the help of DABCO. Then, it undergoes aza-Michael reaction with α,β-unsaturated aldehyde to form transient carbanion. The ring closure occurs leading to four-membered transient 1,2-thiazetidine, from which the sulfonyl moiety is…

The first theoretical investigation on TMSOTf-promoted cascade reaction of propargyl alcohol and protected tryptamine was provided by our DFT calculation. First, propargyl alcohol is activated by TMSOTf resulting in silyl ether accompanied by release of triflic acid. Then silyl ether undergoes Meyer-Schuster re-arrangement generating allenic intermediate and HOSiMe3. Hydroxyl is transferred from the latter to ter-minal alkyne carbon along with recovered TMSOTf. Subsequently, the…

Our DFT calculation provided the first theoretical investigation on TfOH-mediated cascade cyclization from ethyl (E)-2-(2,3-diphenyl-1H-inden-1-ylidene)acetate. The triple bond was activated via protonation forming carbocation intermediate followed by rate-limiting 6-endo-dig cyclization resulting in six-membered ring. The naphthalene ester was generated via aromatization and concomitant recover of TfOH. The ester group is activated under acidic condition, from which two paths are…

Our DFT calculation provided the first theoretical investigation on Lewis/Brønsted acids-catalyzed syntheses of bicyclo[2.1.1]hexane and spirocyclic compound from disubstituted BCB and ester activated quinone. For [2π + 2σ] cycloaddition with Ni(OTf)2 , BCB was activated as nucleophile to attack quinone initially. Then bicyclic product was achieved via cyclization. For (3 + 2) cycloaddition with DTBP, the dehydrogenation of BCB and aromatization of quinone is promoted owing to enhanced…

Our DFT calculation provided the first theoretical investigation on Pd(OAc)2-catalyzed spiro cyclisation of sulfonamide with maleimide. Initially, Pd(OAc)2 is coordinated with quinoline leading to first N-Pd bond. Subsequently, via coordination of sulfonamide to Pd, the second N-Pd bond is generated after liberation of first acetic acid AcOH. Then C-Pd bond is formed by activation of γ-C(sp3)−H bond during formation of key five-membered ring intermediate together with leaving of second AcOH.…