A class of small molecule fluorophores, 2-iminocoumarin-3-carboxamide derivatives, has been developed by a rapid microwave-assisted process. These fluorescent probes are cell membrane permeable with low cytotoxicity and ...
An efficient method for the preparation of siRNAs modified with ribo-like North bicyclo[3.1.0]hexane pseudosugars is described. The combined use of 2'-O-(2-cyanoethoxymethyl) (CEM) and 2'-O-TBDMS protection was successfu...
DFT calculations predict that the [8 + 2]cycloaddition reaction between ketenes and 8-azaheptafulvenes occurs stepwise through antiaromatic zwitterionic intermediates. With adequate modifications of both the electronic p...
A cross ene-yne metathesis has been achieved at a nearly 1:1 stoichiometry of the unsaturated reactants. This allowed the use of more complex alkene reactants without sacrificing excess alkene reactant. In the alkene, di...
Petasis reactions of substituted styrenylboronic acids and glyoxylic acid, employing tert-butylsulfinamide as the 'amine' component, proceed with high stereoselectivity to produce beta,gamma-dehydrohomoarylalanine deriva...
Three novel 1-alkyldaphnane-type diterpenes, stelleralides A-C (4-6), and five known compounds were isolated from the roots of Stellera chamaejasme L. The structures of 4-6 were elucidated by extensive spectroscopic anal...
(3R,4R,5R)-2-Imino-3,4-dihydroxy-5-hydroxymethylpiperidine hydrocloride or Isofagomidine was synthesized from D-arabinose in 12 steps and an overall yield of 9.9%. The synthesis proceeded by introduction of an aminomethy...
A palladium-catalyzed decarboxylative coupling of potassium cyanoacetate with aryl bromides and chlorides is described. The reaction conditions feature the absence of additional strong inorganic bases and provide ester f...
First syntheses of C6,7 and C7 enantiopure cocaine analogues were achieved from D-(-)-ribose via a trans-acetonide controlled endo-selective intramolecular nitrone-alkene cycloaddition (INAC) as the key step. This synthe...
A method to ribosylate adenosine on the 2' hydroxyl function in an alpha-selective fashion and in good yield is presented. Protective groups chosen for the acceptor and donor used in this glycosylation not only direct al...
2-Difluoromethylene-4-methylenepentanoic acid (DFMPA), a seemingly deviated analog of 2-oxoglutaric acid (2-OG), could surprisingly mimic its signaling function in cyanobacteria. Computer modeling revealed the favorable ...
It is reported that stable glycosyl sulfonium salts can be generated via direct anomeric S-methylation of ethylthioglycosides. Mechanistically, this pathway represents the first step in the activation of thioglycosides f...
A concise asymmetric synthesis of (+)-aphanorphine has been achieved via a new enantioconvergent strategy. A racemic gamma-aminoalkene derivative is transformed into a 1:1 mixture of enantiomerically enriched diastereome...
The combination of Fe(OAc)(2) and an electron-donating, sterically hindered pyridyl bisimine ligand catalyzes the cycloaddition of alkynenitriles and alkynes. A variety of substituted pyridines were obtained in good yiel...
A concise and efficient strategy for the construction of the heptacyclic core of the chloranthaceae family has been developed. The key strategy comprises an S(N)2-type intramolecular nucleophilic substitution and a biomi...
Highly enantioselective gem-chlorofluorination of active methylene compounds was carried out by using a copper(II) complex of a chiral spiro pyridyl monooxazoline ligand. This reaction yielded alpha-chloro-alpha-fluoro-b...