An enantio- and diastereodivergent [2+2+1] annulation reaction of allyl ketones, acidic methylene compounds, nitroalkenes to assemble highly functionalized cyclopentanes from readily available substances enabled by asymmetric relay catalysis chiral bifunctional squaramide palladium complex has been established. This method showcases that ketones can serve as latent 1,2-dication synthons via a l...

A concise synthetic strategy has been developed for the synthesis of the macrolactone core 2 of a unique polyketide callyspongiolide 1. The key features of the strategy included an Evan's asymmetric alkylation, diastereoselective Michael type alkylation, Brown's asymmetric allylation reaction, an allylic alkylation of an activated Z-allylic alcohol and an intramolecular Z-selective intramolecul...

A but-3-yn-2-one-based 7-diethylaminocoumarin dye was exploited as a fluorescent probe to specifically detect Cys over Hcy/GSH in pure PBS buffer. The probe itself is nonfluorescent due to the donor-excited photoinduced electron transfer (d-PET) process. The Cys-induced Michael addition-rearrangement cascade reaction leads to an amino-substituted product with strong fluorescence due to inhibiti...

The organocatalytic enantioselective desymmetrization reaction by means of an intramolecular (hetero)Michael addition is a useful strategy for the creation complex carbo- and heterocycles with generation multiple stereocenters in very simple manner. carbon, oxygen nitrogen nucleophiles to prochiral substrates bearing electronically deficient olefins takes place presence organocatalysts, such as...

an efficient synthesis of some novel coumarin derivatives via 1, 4- michael addition of indole to coumarin chalcones catalyzed by cellulose sulphonic acid (csa) under solvent free conditions is described. the corresponding michael addition products were obtained in good to excellent yield. the synthesized compounds were screened for their antibacterial activity against e. coli, s. aureus and an...

An approach to the intramolecular Diels-Alder reaction has led to a cascade synthesis of complex carbocycles composed of three fused rings and up to five stereocenters with complete stereocontrol. Computational analysis reveals that the reaction proceeds by a Michael/Michael/cyclopropanation/epimerization cascade in which size and coordination of the counterion is key.