2713-33-9Relevant academic research and scientific papers
Cellulose as recyclable organocatalyst for ipso-hydroxylation of arylboronic acids
Laskar, Khairujjaman,Paul, Subham,Bora, Utpal
, (2019/08/26)
Cellulose catalyzed oxidative hydroxylation of aryl and hetero-arylboronic acids to the corresponding phenols under metal and base free strategy has been demonstrated. The sustainable ipso-hydroxylation takes place using hydrogen peroxide as an oxidant in water under mild condition in shorter period of time. Interestingly, easy recovery and reusability of heterogeneous catalyst without significant loss in catalytic yield makes the protocol environmentally benign.
Probing synergy between two catalytic strategies in the glycoside hydrolase O-GlcNAcase using multiple linear free energy relationships
Greig, Ian R.,Macauley, Matthew S.,Williams, Ian H.,Vocadlo, David J.
supporting information; experimental part, p. 13415 - 13422 (2010/01/16)
Human O-GlcNAcase plays an important role in regulating the post-translational modification of serine and threonine residues with β-O-linked N-acetylglucosamine monosaccharide unit (O-GlcNAc). The mechanism of O-GlcNAcase involves nucleophilic participation of the 2-acetamido group of the substrate to displace a glycosidically linked leaving group. The tolerance of this enzyme for variation in substrate structure has enabled us to characterize O-GlcNAcase transition states using several series of substrates to generate multiple simultaneous free-energy relationships. Patterns revealing changes in mechanism, transition state, and rate-determining step upon concomitant variation of both nucleophilic strength and leaving group abilities are observed. The observed changes in mechanism reflect the roles played by the enzymic general acid and the catalytic nucleophile. Significantly, these results illustrate how the enzyme synergistically harnesses both modes of catalysis; a feature that eludes many small molecule models of catalysis. These studies also suggest the kinetic significance of an oxocarbenium ion intermediate in the O-GlcNAcase-catalyzed hydrolysis of glucosaminides, probing the limits of what may be learned using nonatomistic investigations of enzymic transition-state structure and offering general insights into how the superfamily of retaining glycoside hydrolases act as efficient catalysts.
Enzymatic Baeyer-Villiger oxidation of benzaldehydes
Moonen, Marielle J. H.,Westphal, Adrie H.,Rietjens, Ivonne M. C. M.,Van Berkel, Willem J. H.
, p. 1027 - 1034 (2007/10/03)
The selectivity of the chemical Baeyer-Villiger oxidation of benzaldehydes depends on steric and electronic factors, the type of oxidizing agent and the reaction conditions. Here we report on the enzymatic Baeyer-Villiger oxidation of fluorobenzaldehydes
Selective and one-pot formation of phenols by anodic oxidation
Fujimoto, Kazuo,Tokuda, Yuichiro,Maekawa, Hirofumi,Matsubara, Yoshiharu,Mizuno, Takumi,Nishiguchi, Ikuzo
, p. 3889 - 3896 (2007/10/03)
Direct monohydroxylation of benzene and substituted benzenes was successfully performed by anodic oxidation to form the corresponding phenol derivatives in good yields. The anodic oxidation was generally carried out in a mixed solvent of trifluoroacetic acid and dichloromethane containing triethylamine using a divided cell equipped with a platinum plate as the anode, a carbon rod as the cathode. Benzene derivatives having electron withdrawing groups were suitable for the present electrochemical oxidation. It was clarified that aryltrifluoroacetates were formed as the initial products from the reaction of the radical cations, generated by one electron transfer from the substrates, with trifluoroacetic acid, followed by hydrolysis during work-up to give the corresponding phenols.
SYNTHESIS AND SOME PROPERTIES OF 3,4-DIFLUOROPHENYL TRANS-4 prime -SUBSTITUTED CYCLOHEXANE-1 prime -CARBOXYLATES.
Takatsu,Takeuchi,Sato
, p. 165 - 180 (2007/10/02)
A new series of 3,4-difluorophenyl trans-4 prime -substituted cyclohexane-1 prime -carboxylates was synthesized in order to achieve a nematic compound of positive dielectric anisotropy and low viscosity. The effect of fluoro substituents on mesomorphic and physical properties was established by comparing these compounds with other fluorinated nematic compounds.
