A new complexity building photoinduced cascade which amounts to an unprecedented formal [4+2+2+2] cycloaddition topology is developed access complex nitrogen polyheterocycles. This photocascade initiated by the excited state intramolecular proton transfer (ESIPT) in aromatic amino ketones with tethered dual unsaturated pendants, i.e. pyrrole and alkenic moieties, resulting formation of four ?-b...

This Account covers the design of Ru catalysts and ligands. Two classes of chiral phosphine ligands are prepared: the electron-rich trans-2,4-substituted phosphetanes, readily available from optically pure 1,3-diol cyclic sulfates, and atropoisomeric ligands (SYNPHOS, MeO-NAPhePHOS, bearing heterotopic biaryl moieties, and a chiral water-soluble diguanidinium binaphthyl diphosphine, Digm-BINAP)...

Addition of lithiated dithianes to diaryl ketones, potential electron-transfer sensitizers, disrupts conjugation between the two aromatic moieties, effectively masking the sensitizer. A novel photoamplification strategy is developed based on photosensitized cleavage in such adducts, where each fragmentation event releases more diaryl ketone, capable of sensitization. As a result, mass release o...

We developed a new method for stereoselective construction of an all-carbon quaternary stereogenic center on a carbocyclic ring based on regio- and stereoselective S(N)2' alkylation reactions of γ,δ-epoxy-α,β-unsaturated cyclic ketones. Treatment of the ketones, which were readily prepared in enantiomerically pure form by means of aldol condensations between 3-ethoxy-2-cycloalkenones and α,β-ep...

The synthesis of halogenated and trifluoromethylated α-boryl ketones via a one-pot oxidative difunctionalization of alkenyl MIDA boronates is reported. These novel densely functionalized organoborons bearing synthetically and functionally valuable carbonyl, halogen/CF3 and boronate moieties within the same molecule are synthetically challenging for the chemist, but have great synthetic potentia...

synthesized from dipeptidyl chloromethyl ketones or methyl ketones. According to this novel procedure, various functional groups could be introduced into positions 3 and 6 of 1,2-dihydropyrazin-2-one by using appropriate amino acids (Chart 2). It had been assumed that the formation of the 1,2-dihydropyrazin-2-one ring from dipeptidyl chloromethyl ketones proceeded according to the mechanism sho...

Azolium cumulenolates are a special type of intermediates in N-heterocyclic carbene catalysis. They contain elongated linear structures with three contiguous C=C bonds and sterically unhindered α-carbon atoms. These structural features make it difficult to develop enantioselective reactions for these intermediates. Here we disclose the first carbene-catalyzed highly addition azolium cumulenolat...

Glutamylglycinylarginyl chloromethyl ketone, tyrosylglycinylarginyl chloromethyl ketone, and phenylalanylprolylarginyl chloromethyl ketone have been labeled at their amino termini using fluorescein, rhodamine-X, lissamine-rhodamine, pyrene, and the 1,5-, 2,5-, and 2,6-dimethylaminonaphthalene-l-sulfonyl moieties. These peptidyl chloromethyl ketones have also been modified by incorporation of bi...

Structure, and consequently properties, of ionic liquids can be easily tailored by changing cation/anion combinations and/or attaching functional groups. By grafting enantiopure moieties to the framework liquid it is possible prepare bioinspired chiral molecules that serve as a reaction medium, additive or even asymmetric catalyst. In this context, new (CILs), based on biomolecules, such aminoa...