Molecular design of lipophilic disalicylic acid compounds with varying spacers for selective lead(II) extraction.

Lipophilic disalicylic acids 5,5'-decyl-2,2'-[1,2-ethanediylbis(oxy)]bisbenzoic acid (1), 5,5'-decyl-2,2'-[1,3-propanediylbis(oxy)]bisbenzoic acid (2), 5,5'-decyl-2,2'-[oxybis(1,2-ethanediyl-oxy)]bisbenzoic acid (3), 3,5-bis[2'-(2''-carboxyphenoxy)ethyl]-4-oxahexacyclo-[5.4.1.

Pharmacology and structure-activity relationships of bioactive polycyclic cage compounds: a focus on pentacycloundecane derivatives.

The chemistry of organic polycyclic cage compounds has intrigued medicinal chemists for over 50 years, yet little is published about their pharmacological profiles. Polycyclic cage compounds have important pharmaceutical applications, ranging from the symptomatic and proposed curative treatment of neurodegenerative diseases such as Parkinson's and Alzheimer's disease (e.g.

Complexation of silver and co-recovered metals with novel aza-crown ether macrocycles by electrospray ionization mass spectrometry.

Electrospray ionization mass spectrometry (ESI-MS) is used to evaluate the metal binding selectivities of an array of novel caged macrocycles for silver, gold, copper, nickel, zinc, iron, lead, manganese and alkali metal ions. It is found that five of the new compounds display silver selectivity, and their relative affinities for various metals depend on the type, number, and arrangement of heteroatoms (N, O), the cavity size, and the presence of aromatic substituents. Alkali metal cation binding studies are used to evaluate the size-selectivities of the cavities of the macrocycles.

Metal complexation of thiacrown ether macrocycles by electrospray ionization mass spectrometry.

In the present study, electrospray ionization mass spectrometry is used to evaluate the metal-binding selectivities of an array of novel caged macrocycles for mercury(II), lead(II), cadmium(II), and zinc(II) ions. In homogeneous methanol/chloroform solutions as well as extractions of metals from aqueous solution by macrocycles in chloroform, it is found that the type of heteroatom (S, O, N), cavity size, and presence of other substituents influence the metal selectivities. Several of the macrocycles in this study bind mercury ion very selectively and efficiently in the presence of many other metal ions and have an avidity toward mercury that was tunable by the size and combination of heteroatoms in the macrocycle ring and the number of cage groups attached.

On the origins of diastereofacial selectivity of [4 + 2] cycloadditions in cage- annulated and polycarbocyclic diene/dienophile systems.

pi-Facial diastereoselectivities in Diels-Alder reactions that involve pi-facially differentiated cyclohexa-1,3-dienes, i.e., 3-substituted or 3-10-disubstituted hexacyclo-[10.

Synthesis of novel cage oxaheterocycles.

m-CPBA-promoted Baeyer-Villiger oxidation of pentacyclo[6.3.0.

Evaluation of alkali metal binding selectivities of caged aza-crown ether ligands by microelectrospray ionization/quadrupole ion trap mass spectrometry.

Microelectrospray ionization mass spectrometry (MESI-MS) is used to evaluate alkali metal binding selectivities of a variety of macrocyclic compounds. Well-studied crown ethers are used to validate the MESI-MS method. A quantitative correlation between MESI mass spectral ion intensities and solution equilibrium distributions of complexes is obtained for the mixtures containing a single host and different alkali metal guest ions.

Evaluation of binding selectivities of caged crown ligands toward heavy metals by electrospray ionization/quadrupole ion trap mass spectrometry.

Electrospray ionization (ESI)/quadrupole ion trap mass spectrometry is used to evaluate the heavy metal binding selectivities of five caged crown ethers and two polyether reference compounds in methanol solution. The binding preferences for Hg2+, Pb2+, Cd2+, and Cu2+ were analyzed by comparison of ESI mass spectral intensities with the aim of developing this method for the rapid screening of binding selectivities of new synthetic ligands. The cage compounds preferentially bind Hg2+, except for the cage cryptand derivative, which favors Pb2+.

Computational studies of inclusion phenomena and synthesis of a novel and selective molecular receptor for 1,4-disubstituted benzenes and 4,4'-disubstituted biphenyls.

A new tetracationic molecular receptor has been synthesized and studied by semiempirical molecular orbital theory. This novel macrocycle, 1(4+), derived from pentacyclo[5.0.

Reactions of N-(Ethoxycarbonyl)-3-halo-3-(halomethyl)azetidines with DBU. The Halogen Dance.

Reaction of N-(ethoxycarbonyl)-3-(bromomethyl)-3-chloroazetidine (3) with DBU results in the formation of two haloalkenes, i.e., N-(ethoxycarbonyl)-3-(bromomethylene)azetidine and N-(ethoxycarbonyl)-3-(chloromethylene)azetidine (4a and 4b, respectively).