نتایج جستجو برای: regioselective
تعداد نتایج: 2974 فیلتر نتایج به سال:
A general and regioselective method for the chlorination of activated arenes has been developed. The transformation uses iron(III) triflimide as a powerful Lewis acid for the activation of N-chlorosuccinimide and the subsequent chlorination of a wide range of anisole, aniline, acetanilide, and phenol derivatives. The reaction was utilized for the late-stage mono- and dichlorination of a range o...
We report on a 'green' method for the utilization of carbon dioxide as C1 unit for the regioselective synthesis of (E)-cinnamic acids via regioselective enzymatic carboxylation of para-hydroxystyrenes. Phenolic acid decarboxylases from bacterial sources catalyzed the β-carboxylation of para-hydroxystyrene derivatives with excellent regio- and (E/Z)-stereoselectivity by exclusively acting at the...
Anisotropic nanoparticles can provide considerable opportunities for assembly of nanomaterials with unique structures and properties. However, most reported anisotropic nanoparticles are either difficult to prepare or to functionalize. Here we report a facile one-step solution-based method to prepare anisotropic DNA-functionalized gold nanoparticles (a-DNA-AuNP) with 96% yield and with high DNA...
The regioselective C-2-O-acrylation and metacrylation of methyl 4,6-O-benzylidene-alpha-D-glucopyranoside and methyl 4,6-O-benzylidene-alpha-D-galactopyranoside through their corresponding organotin intermediates have been studied. Regioselectivity was achieved through the formation of a tin chelate of the 2,3-diols. Thus, methyl 4,6-O-benzylidene-alpha-D-glucopyranoside and methyl 4,6-O-benzyl...
We identify and control the photoreaction paths of self-assembled monolayers (SAMs) of thiolate-linked anthracene phenylethynyl molecules on Au substrate surfaces, and study the effects of nanoscale morphology of substrates on regioselective photoreactions. Two types of morphologies, atomically flat and curved, are produced on Au surfaces by controlling substrate structure and metal deposition....
Highly regioselective acylation of helicid with fatty acid vinyl esters catalyzed by the lipase from Thermomyces lanuginosus has been successfully performed for the first time. For the enzymatic caproylation of helicid, under the optimal conditions, initial reaction rate was 33.2 mM/h, and substrate conversion and regioselectivity were greater than 99%. In addition, the acyl recognition of the ...
The C4 methyl group of guaiazulene can be transformed into the corresponding aldehyde in a chemo- and regioselective manner. This is versatile building block from which C4-alkenylated guaiazulenes that exhibit halochromism may accessed.
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