نتایج جستجو برای: intramolecular
تعداد نتایج: 13309 فیلتر نتایج به سال:
The total synthesis of lycopalhine A has been accomplished. The synthesis features construction of the tricyclic system via cleavage of a cyclopropane ring and an ensuing intramolecular Michael addition, stereoselective introduction of a 2-aminoethyl moiety via a reaction of allyltrimethylsilane to a sulfonyliminium ion, and a stereoselective intramolecular aldol reaction.
[reaction: see text]. The copper acetate mediated intramolecular O-arylation of phenols with phenylboronic acid pseudopeptides is the key step in the preparation of macrocyclic biphenyl ether hydroxamic acid inhibitors of collagenase 1 and gelatinases A and B. The intramolecular macrocyclization was found to be mild and tolerant of common chemical functionality. This methodology should provide ...
Proton controlled intramolecular PET from an aniline moiety to a squaraine chromophore, attached to podand chains is reported, which to our knowledge is the first example where a squaraine dye is involved as an electron acceptor in an intramolecular PET process, and has implication in the design of PET based sensors.
Thio-Ugi reactions are described as an excellent synthetic tool for the synthesis of sterically highly hindered endothiopeptides. S-Methylation and subsequent amidine formation can be carried out in an inter- as well as in an intramolecular fashion. The intramolecular approach allows the synthesis of the bottromycin ring system in a straightforward manner.
With the mediation of phosphine, the direct intramolecular coupling of two electrophiles - alkyl halides with electron-deficient olefins - has been successfully realized in an intramolecular conjugate addition manner. The reaction provides a new approach for the synthesis of chromans and relevant analogues.
A synthetic route developed for the preparation of the A-ring of Taxol family of molecules is reported. By means of an intramolecular Diels-Alder reaction an asymmetric approach to this ring has been accomplished. Also, initial studies to prepare the A ring using an intramolecular Diels-Alder reaction have been successful.
The rhodium-catalyzed intramolecular direct arylation of imidazole and benzimidazole derivatives via double C-H bond activation is described. This approach provides new access to a wide range of imidazo and benzimidazo[2,1-a]isoquinoline derivatives in moderate to high yields. This reaction provides an alternative method to the known Pd-catalyzed intramolecular oxidative cross-coupling reactions.
Homologous recombination and deletions occur during retroviral replication when reverse transcriptase switches templates. While recombination occurs solely by intermolecular template switching (between copackaged RNAs), deletions can occur by an intermolecular or an intramolecular template switch (within the same RNA). To directly compare the rates of intramolecular and intermolecular template ...
One of the limitations of the PKR is the poor regioselectivity observed in intermolecular reactions where unsymmetrical alkynes and alkenes can give rise to mixtures of four constitutional isomers. Inherent regiocontrol of the intramolecular PKR of enynes 3 to form bicyclic cyclopentenones 4 (Scheme 1) makes this variant appealing and it has been actively investigated since its inception in 198...
We investigate electron transport through series and parallel intramolecular circuits in the framework of the multi-level Redfield theory. Based on the assumption of weak monomer-bath couplings, the simulations depict the length and temperature dependence in six types of intramolecular circuits. In the tunneling regime, we find that the intramolecular circuit rule is only valid in the weak mono...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید