The present communication reports the chemistry of three linear triborane(5) compounds possessing bulky diamino substituents on the terminal boron atoms. Fluorotriborane 2 was synthesized by a reaction of boryllithium and BF(3)·OEt(2). Halogen exchange reaction of 2 took place by a treatment with ClSiMe(3) to give the corresponding chlorotriborane(5) 3. Addition of silver tetraarylborate to 3 i...

A practical access to four new halogen-substituted pyrrole building blocks was realized in two five synthetic steps from commercially available starting materials. The target compounds were prepared on a 50 mg 1 g scale, and their conversion nanomolar inhibitors of bacterial DNA gyrase B demonstrated for three the showcase usefulness such chemical motifs medicinal chemistry.

The title compounds, benzyl 4-(3-chloro-2-fluorophenyl)-2-methyl-5-oxo-4,5,6,7-tetrahydro-1H-cyclopenta[b]pyridine-3-carboxylate, C(23)H(19)ClFNO(3), (I), and 3-pyridylmethyl 4-[2-fluoro-3-(trifluoromethyl)phenyl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, C(26)H(24)F(4)N(2)O(3), (II), belong to a class of 1,4-dihydropyridines whose members sometimes display calcium mod...

In this review we cover recent developments in fluorescent and colorimetric anion sensors. These systems employ a range of different non-covalent interactions including hydrogen- halogen-bonding, Lewis acidic boron-based sensors, metal-based charged systems, compounds that use anion-pi to stabilise complexes, photoswitchable the excimers molecular logic gates sensing. Recent anion-selective che...

LACRIMATORS are compounds which, in gaseous form in extremely small concentrations, act as conjunctival irritants. Chemically, almost all are halogenized organic substances. Because of a loose mesomer connexion the halogen atom is very reactive. Duke-Elder (1954) listed more than ten liquid or solid tear producers. Chloracetophenon (Fig. 1) has been that most frequently used for many years, and...

An ab initio HF MO theory is applied to CuX, CuX2 (X = F and Cl) and (CuCl)3. Although the detailed sequence of energy levels depends upon the basis set used, high-lying orbital energy levels have largely halogen p-like character, whereas low-lying orbital energy levels have largely Cu 3 d-like character. This is in agreement with the chemical intuition of a highly ionic character of these comp...

Z. Naturforsch. 54 b, 573-576 (1999); eingegangen am 28. Dezember 1998 Fused Salts, Monosilane, Methylsilanes, Hydrosilylation, Chloroaluminate Silanes of technical interest as starting compounds for semiconducting materials or hydrosi­ lylation reactions, (CH3)xSiH4_x (x = 0, 1,2, 3), are obtained by direct hydrogenation of the corresponding chlorosilanes in the presence of various interstitia...

Ch~lating agents are compounds that fonn metal complexes characterized b)' ring struaurcs ilIusuated in Fig, I.I.~. j In type I th~ metal is coordinated to th~ four nitrogcns of two molecules of ethylcn~ diamine, giving rise to a d1arged cmuble ringed compla ,,'ith cbIorid~ nNtralizing th~ two charges, I Other types of dldating oomplcxes indudc t}"pe II. "ith 81 inm-molccular hydrogen bridge. a...

Pyridines carrying heterosubstituents (such as carboxy, amido, amino, alkoxy or trifluoromethyl groups or solely individual halogen atoms) can be readily and site selectively metalated. Subsequent reaction with a suitable electrophile opens rational access to a wealth of new building blocks for the synthesis of biologically active compounds. This approach relies on organometallic methods, which...

A comprehensive survey has been made of all fatty acids containing halogen atoms covalently bonded to carbon and which are deemed as naturally occurring. Generally thought to be minor components produced by many different organisms, these interesting compounds now number more than 300. Recent research, especially in the marine area, indicates this number will increase in the future. Sources of ...