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Substituted carboxyphthalocyanines (I), wherein both the tert-butyl and carboxyl groups located in the four isoindole rings are located independently in any of the four positions of the corresponding benzene ring of each isoindole ring, its regioisomers an ...
This chapter reviews bicyclic systems containing two fused five-membered rings with one bridgehead nitrogen and two other heteroatoms (nitrogen, oxygen, and sulfur) in each ring. Among the possible structural backbones, 16 have been so far found in the lit ...
This review presents natural products from cyanobacteria. Several classes of secondary metabolites are highlighted. Toxic metabolites from these prokaryotic photosynthetic organisms include compounds such as microcystin, anatoxin and saxitoxin, which displ ...
Chiral BINOL phosphorochloridites were esterified and amidated with enantiopure 6-hydroxytropinone [6-hydroxy-8-azabicyclo[3.2.1]octan-3-one] cyclic acetal to yield chiral bidentate and monodentate phosphite-phosphoramidite ligands for copper-catalyzed asy ...
To better understand the complex photophysics of the amino acid tryptophan, which is widely used as a probe of protein structure and dynamics, we have measured electronic spectra of protonated, gas-phase tryptophan solvated with a controlled number of wate ...
All twelve indolecarboxylic acids carrying both a fluorine substituent and a carboxy group at the benzo ring have been prepd. either directly from the corresponding fluoroindoles or from the chlorinated derivs. by hydrogen/metal permutation ("metalation"), ...
Coupling of substituted 2-iodoanilines with Me (S)-2-[di(tert-butoxycarbonyl)amino]-5-oxopentanoate, derived from glutamic acid, in DMF in the presence of Pd(OAc)2 and DABCO provides substituted tryptophans in good to excellent yields. [on SciFinder (R)] ...
One-pot synthesis of indoles by a palladium-catalyzed annulation of o-haloanilines and aldehydes has been developed. Coupling of o-iodoaniline with aldehyde is realized under mild ligandless conditions [Pd(OAc)2, DABCO, DMF, 85 DegC], whereas X-Phos is fou ...
The downfield chem. shifts of arene hydrogens (delta 1H) are due only in part to the pi ring current contribution [sigma.dblvert.(pi)]; local framework effects are equally important. Neither proton chem. shifts nor even sigma.dblvert.(pi) tensor elements, ...
We report here a new method to obtain electronic spectra of biomolecular ions that are produced in the gas phase by electrospray and cooled to ~10K in a 22-pole ion trap, and we demonstrate this technique by applying it to protonated tryptophan and tyrosin ...
