Chlorine in an Organic Molecule, a Universal Promoter-Workhorse-Of Reactions.

Due to the electronic configuration of the atom and charge of the nucleus, the chlorine in organic molecules can exert a variety of effects. It can depart as a chloride anion in the process of substitution and elimination, facilitates the abstraction of protons and stabilizes generated carbanions, exerts moderate stabilizing effect of carbenes, carbocations and radicals. There are frequent cases where chlorine substituent promotes more than one transformation.

Analogy of the Reactions of Aromatic and Aliphatic π-Electrophiles with Nucleophiles.

The aim of this essay is to disclose the similarity of a great variety of reactions that proceed between nucleophiles and π-electrophiles-both aromatic and aliphatic. These reactions proceed via initial reversible addition, followed by a variety of transformations that are common for the adducts of both aliphatic and aromatic electrophiles. We hope that understanding of this analogy should help to expand the scope of the known reactions and inspire the search for new reactions that were overlooked.

Interfacial Generation of a Carbanion: The Key Step of PTC Reaction Directly Observed by Second Harmonic Generation.

We present the first unambiguous evidence of the interfacial mechanism of phase-transfer catalysis (PTC) by direct observation of the formation of carbanions in the interfacial region between the aqueous and the organic phase by using a surface-sensitive spectroscopic method known as second harmonic generation (SHG). Ion exchange of carbanions adsorbed at the surface after addition of lipophilic tetraalkylammonium salts (TAA) to organic phase and transport of the lipophilic ion-pairs to the organic phase is observed. Results allow for the formulation of a more detailed mechanism of PTC.

N-(2-Bromo-benz-yl)cinchoninium bromide.

The title compound {systematic name: 1-(2-bromo-benz-yl)-5-ethenyl-2-[hy-droxy(quinolin-4-yl)meth-yl]-1-aza-bicyclo-[2.2.2]octan-1-ium bromide}, C(26)H(28)BrN(2)O(+)·Br(-), is a chiral quater-nary ammonium salt of one of the Cinchona alkaloids.

Phase transfer catalysis in pharmaceutical industry--where are we?

Basic concept of phase transfer catalysis, its specific features and applications in pharmaceutical industry are described.

Synthesis and antibacterial activity of 5-adamantan-1-yl-methyl analogues of trimethoprim.

A series of new trimethoprim [5-(3,4,5-trimethoxy-benzyl)-pyrimidine-2,4- diamine] analogues were prepared by condensation of adamantane-1-carbaldehyde with 3-methoxypropionitrile, followed by reaction of resulting mixture of 2-adamantan-1-ylmethyl-3-methoxy-acrylonitrile and 3-adamantan-1-yl-2-methoxymethyl-acrylonitrile with guanidine, acetamidine and thiourea, respectively. The activity of compounds obtained and sulfamethoxazole, alone and in combination, against several bacterial strains, as well as fungi was investigated.