Last. Anna G. Larina(SPbU: Saint Petersburg State University)H-Index: 9
view all 6 authors...
A diastereoselective synthesis of biologically interesting spirobarbiturates has been achieved via [3 + 2] cycloaddition of alloxan-derived azomethine ylides to 3-R-1,2-diphenylcyclopropenes. With this approach, various spirobarbiturate-3-azabicyclo[3.1.0]hexanes and spirobarbiturate-cyclopropa[a]pyrrolizines were obtained in moderate to good yields with excellent diastereoselectivities. DFT calculations (M11 density functional theory) have been carried out to shed light on the molecular mechani...
The efficient and concise synthesis of cytotoxic 5, 6-dihydro-α-pyrone (+)-brevipolide H has been accomplished in 12 long linear steps with 8.65% overall yield from readily available chiral synthons, D-galactal and L-ethyl lactate. The features of this synthesis are highly diastereoselective Simmons-Smith cyclopropanation and carbohydrate-based chiron approach to rapid access to key 5, 6-dihydro-α-pyrone skeleton.
Last. Matthias Koch(BAM: Bundesanstalt für Materialforschung und -prüfung)H-Index: 20
view all 3 authors...
Abstract Alternariol (AOH) and alternariol-9-monomethyl ether (AME) are two secondary metabolites of Alternaria fungi which can be found in various foodstuff like tomatoes, nuts, and grains. Due to their toxicity and potential mutagenic activity the need for the development of high-throughput methods for the supervision of AOH- and AME-levels is of increasing interest. As the availability of both native and labeled AOH and AME analytical standards is very limited we herein wish to present a nove...
Last. Fu-She Han(CAS: Chinese Academy of Sciences)
view all 3 authors...
Chiral alcohols are important synthetic intermediates or building blocks for the diverse synthesis of drugs, agrochemicals, and natural products. Asymmetric reduction of prochiral ketones has been the most popularly investigated method for accessing chiral alcohols. In this regard, the organocatalyzed asymmetric reduction as a complementary of transition-metal- and enzyme-catalyzed reactions have attracted tremendous interest in the past decades due to the nature of metal-free and easy operation...
The Piancatelli reaction, which is the rearrangement of 2-furylcarbinol to cyclopentenone, involves a key furanoxonium ion intermediate and a furan ring opening-4π electrocyclization process. In recent years, the original oxa-Piancatelli reaction has been extended to a large family of aza- and carbo-Piancatelli reactions and related cascade processes, providing a powerful platform for the construction of diverse functionalized cyclopentenones and polycyclic cyclopentanones. Meanwhile, chiral Bro...
Last. Liang Cheng(CAS: Chinese Academy of Sciences)H-Index: 133
view all 5 authors...
We have developed an efficient fragment splicing method for the construction of multiple nucleobase-terminated monomers. null Conformationally fixed rod, trigonal planer and tetrahedral thymine and adenine structures were generated in moderate to good yields, which will serve as inspiring examples for exploration of nucleobases as natural hydrogen-bond components in supramolecular chemistry.
In this work, a convenient synthetic protocol for the unprecedented N-hydroxylation of proline residue in Melanostatin (MIF-1) neuropeptide is reported. This methodology is grounded on the incorporation of N-(cyanoethyl)prolyl residue followed by on-site oxidation by Cope elimination with m-chloroperbenzoic acid, exploring the unrecognized dual role of the cyanoethyl group as an effective N-protecting group under peptide synthesis conditions and as a suitable leaving group during the chemoselect...
The palladium-catalyzed synthesis of indole/benzofuran-containing diarylmethanes starting from indolylmethyl or benzofuranylmethyl acetates with boronic acids has been investigated. The success of the reaction is influenced by the choice of precatalyst: with indolylmethyl acetates the reaction works well with [Pd(η3-C3H5)Cl]2/XPhos while with benzofuranylmethyl acetates Pd2(dba)3/XPhos is more efficient. The good to high yields and the simplicity of the experimental procedure make this protocol ...
Last. Paul Knochel(LMU: Ludwig Maximilian University of Munich)H-Index: 125
view all 6 authors...
The treatment of 3-halopyridines (Cl, Br) bearing an R-substituent in position 2 (R = OEt, NEt2, N-piperidyl, or SEt) or in position 5 (R = OMe, OEt, SEt, NMe2, NEt2, or aryl) with KHMDS and an amine at 25 °C for 12 hours in THF provided regioselectively 3- and 4-aminated pyridines in 56–90% yields. The reaction of 3-bromo-2-diethylaminopyridine with various alcohols in the presence of t-BuOK/18-crown-6 in THF at 80 °C for 20–60 hours gave various 4-alkoxy-2-diethylaminopyridines in 61–81% yield...
We use cookies to improve your online experience. By continuing to use our website we assume you agree to the placement of these cookies. To learn more, you can find in our Privacy Policy.