A new approach for the convenient synthesis of dibenzazepinones is reported. The key step is the formation of the seven-membered ring through palladium-catalyzed intramolecular arylation of an anilide enolate. The reacti...
Ortho lithiation of N-benzamido-P,P,P-triaryliminophosphoranes through deprotonation with alkyllithium bases was achieved with ortho-C=O and ortho-P=N chemoselectivity. However, the synthetic scope of these processes was...
Electron paramagnetic resonance imaging (EPRI) using nitroxides is an emergent imaging method for studying in vivo physiology, including O-2 distribution in various tissues. Such imaging capabilities would allow O-2 mapp...
N-(alpha-Aminoalkyl)tetrazoles exist in solution as equilibrium mixtures of N1 and N2 tautomers. The position of equilibrium depends significantly on the polarity of the solvent and the substituents in the tetrazole ring...
The air-stable complex Pd(eta(3)-allyl)(DTBNpP)Cl (DTBNpP = di(tert-butyl)neopentylphosphine) serves as a highly efficient precatalyst for the arylation of amines and enolates using aryl bromides and chlorides under mild...
The Caribbean sponges of the genus Plakortis, P. halichondrioides, and P. simplex have provided a series of biologically active furanolactones-the plakortones A-D (1-4) from the former sponge and B F (2-6) from the latte...
Heats (enthalpies) of formation of organic compounds are obtained by adding a constant for a functional group to the heat of formation of its hydrocarbon precursor obtained by counting hydrogens, as previously described....
Benzotriazol-1-yl-sulfonyl azide, a new crystalline, stable, and easily available diazotransfer reagent provides N-(alpha-azidoacyl)benzotriazoles convenient for N-, O-, C- and S-acylations. The efficient syntheses of va...
The syntheses of various two- and three-station mannosyl [c2]daisy chains, based on a dibenzo-24-crown-8 macrocyclic moiety and an ammonium, a triazolium, and a mono- or disubstituted pyridinium amide station, are report...
We described in a previous communication a variant of the popular Cu-I-catalyzed azide-alkyne cycloaddition (AAC) process where 5 mol % of Cu(OAc)(2) in the absence of any added reducing agent is sufficient to enable the...
Features of the oxidative cleavage reactions of diastereomers of dimeric lignin model compounds, which are models of the major types of structural units found in the lignin backbone, were examined. Cation radicals of the...
A series of fulvene monoaldehydes were prepared by reacting furan or thiophene carbaldelaydes with an indene-derived enamine in the presence of di-n-butylboron triflate, but considerable difficulties were encountered in ...
The activation parameters for the thermal decomposition of 13 acridinium-substituted 1,2-dioxetanes, bearing an aromatic moiety, were determined and their chemiluminescence emission quantum yields estimated, utilizing in...
The mechanism of ring-opening of epsilon-caprolactone by methanol catalyzed by trifluoromethane and methane sulfonic acids has been studied computationally at the DFT level of theory. For both elementary steps, the sulfo...
Glycine-derived 1H-benzo[e][1,4]diazepin-2(3H)-ones (BZDs) 5d-g featuring C9- and N1-substitution exhibit enantiomerization barriers too high to be measured by H-1 NMR coalescence experiments. To address this problem, we...
Nanohoops are macrocycles formed of aromatic rings linked in a 1,4' fashion. Cycloparaphenylenes 1 and nitrogen analogues formed from the building blocks pyridinyl (2), pyrazinyl (3), pyridazinyl (4), and pyrimidinyl (5)...