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Physicochemical properties constitute a key factor for the success of a drug candidate. Whereas many strategies to improve the physicochemical properties of small heterocycle-type leads exist, complex hydrocarbon skeletons are more challenging to derivatize because of the absence of functional groups. A variety of C-H oxidation methods have been explored on(More)
The site selectivities and stereoselectivities of C-H oxidations of substituted cyclohexanes and trans-decalins by dimethyldioxirane (DMDO) were investigated computationally with quantum mechanical density functional theory (DFT). The multiconfiguration CASPT2 method was employed on model systems to establish the preferred mechanism and transition state(More)
Schleyer's discovery of hyperconjugative aromaticity and antiaromaticity in 5-substituted cyclopentadienes further expanded our understanding of the pervasive influence of aromaticity. Acceptors induce antiaromatic character by Schleyer's negative hyperconjugative aromaticity, and donors have the opposite effect. We computationally explored the Diels-Alder(More)
A highly enantioselective catalytic protocol for the desymmetrization of a wide variety of 2-substituted and 2,2-disubstituted 1,3-diols is reported. This reaction proceeds through the formation of an "ortho ester" intermediate via oxidation of 1,3-diol benzylidene acetal by dimethyldioxirane (DMDO) and the subsequent proton transfer catalyzed by chiral(More)
Enantioselective conjugate additions of arylboronic acids to β-substituted cyclic enones have been previously reported from our laboratories. Air- and moisture-tolerant conditions were achieved with a catalyst derived in situ from palladium(II) trifluoroacetate and the chiral ligand (S)-t-BuPyOx. We now report a combined experimental and computational(More)
Theoretical calculations were performed on the 1,3-dipolar cycloaddition reactions of 24 1,3-dipoles with ethylene and acetylene. The 24 1,3-dipoles are of the formula X≡Y(+)-Z(-) (where X is HC or N, Y is N, and Z is CH(2), NH, or O) or X═Y(+)-Z(-) (where X and Z are CH(2), NH, or O and Y is NH, O, or S). The high-accuracy G3B3 method was employed as the(More)
The rearrangements of 4-substituted bicyclo[2.2.2]oct-5-en-2-yl radicals, generated from the corresponding Diels-Alder adducts with phenylseleno acrylates by radical-induced reductive deselenocarbonylations, give the 2-substituted bicyclo[3.2.1]oct-6-en-2-yl radicals with some substituents, e.g., alkoxy and phenyl, but not for silyloxymethyl or benzyl(More)
The mechanism of C-H activation at metathesis-relevant ruthenium(II) benzylidene complexes was studied both experimentally and computationally. Synthesis of a ruthenium dicarboxylate at a low temperature allowed for direct observation of the C-H activation step, independent of the initial anionic ligand-exchange reactions. A first-order reaction supports an(More)