A convenient procedure was developed for the preparation of 4,5-dihydroimidazole-2-carboxamides by the reaction of monothiooxamides with ethylenediamine.

Depending on the substituent at C-4 (OH or MeNH) 3-acyl-5,6-dihydropyridinones 1 and 2 react with hydroxylamine to give either isoxazolo[5,4-c]pyridinone 3 and isoxazolo[4,3-c]pyridinone 4, respectively. The tautomeric equilibria of 1 and 2 are investigated by means of NMR spectroscopy and density functional calculations. The mechanisms of formation of 3 and 4 are interpreted with the aid of semiempirical molecular orbital calculations.

The T1 linker for the attachment of arenes has been described. Various transformations yielded modified arenes. The cleavage from the resin has been conducted to give hydrocarbons ("Traceless linker"), heterocycles (Richter reaction), arylated, alkenylated and alkylated arenes (Heck cleavage protocol), haloarenes, phenols, biaryls and azo compounds. This method is applicable to parallel synthesis and automation.

Compounds containing phosphine and phosphinimide units provide bifunctionality from a "soft" phosphorus(III) center (which is predisposed for combination with soft metals) and a "hard" nitrogen center (which is predisposed for combination with early transition metals) so that the complex formation process is favored in a variety of situations. Ten years ago it was reported[1] that tungsten and molybdenum carbonyls react with N-trimethylsilyl[(diphenylphosphino)methyl] diphenylphosphinimide 1 to give the cyclometallophosphinimide phosphanes 2 and 3. In the course of our current research on the chemistry of [(diphenylphosphino)methyl]diphenyl phosphinimides we attempted a similar coordination of some N-aryl derivatives 4 under similar reaction conditions. In our hands, such small variation of the starting phosphinimides (N-aryl instead of N-trimethylsilyl) with respect to the scheme above resulted in notably different reaction products. Thus, the reaction of N-aryl[(diphenylphosphino)methyl]diphenylphosphinimides 4[2] with W(CO)5THF[3] gave rise to the previously unknown tungsten complexes 5 albeit in low yields. Compounds 5 precipitated out from the reaction medium as yellow solids and were isolated by filtration in virtually pure state.

Flash vacuum pyrolysis (FVP) and oxidative decarboxylation methods were used as a novel synthetic routes to dibenzobarrelene and pyrimidinobenzobarrelenes. A computational study of these reactions was conducted in order to gain more insight into the reaction mechanism.

Approaches to the synthesise of rigid molecular rods containing syn-facially positioned 7-oxa functionality the building BLOCK 12 was identified by molecular modelling as a suitable starting substrate. However, once synthesised, 12 was found to be unstable under the reaction conditions used in an attempt to create rigid rods. This included such coupling protocols as the epoxide based ACE reaction as well as the s-tetrazine system. The foundations have now been laid for future incorporation of 12 into rigid rods.

Furan 16 is shown to react under high pressure (14 kbar) with dimethyl 7-isopropylidene norbornadiene-2,3-dicarboxylate 4 to form two 1:1-adducts 17 and 19 (only 17 isolated) by exclusive reaction at the ester-substituted p -bond and 2:1-products 18 and 20 (X-ray analysis) by further in situ cycloaddition of furan 16 at the newly formed 7-oxa norbornene p-bond of the 1:1-adducts. Similar 1:1-adducts 26, 27 and 2:1-adducts 28, 29 were obtained in the high pressure addition of furan 16 with tetramethyl 7-isopropyl idenenorbornadiene-2,3,5,6-tetracarboxylate 5.

A particularly flexible general way to synthesize 1-hydroxy cycloalkenecarboxylic acid derivatives from 2-tert-butyl-2-methyl-1,3-dioxolan-5-one, a chiral equivalent of glycolic acid, is reported. The method is based on a double enolate alkylation of the glycolate derivative followed by ring closing metathesis. A formal synthesis of (-)-quinic acid is reported to demonstate the potential of this approach

Various applications of the cycloaddition/N-acyliminium ion tandem cyclization cascade are outlined in this electronic symposium on synthetic organic chemistry. The key step in the process involves the generation of a reactive N-acyliminium ion by fragmentation of an amino substituted [4+2]-cycloadduct. The successful synthesis of a number of alkaloids by this sequence of reactions reveals the usefulness and importance of this unique domino cascade.

N-Methyltyramine and its alkyl or benzyl ethers are common intermediate products in the syntheses of narwedine, and galanthamine alkaloids [1-8]. They are usually produced from the corresponding arylacetamides by lithium aluminium hydride reduction. In order to avoid application of inflammable lithium aluminium hydride bulgarian scientists have transformed arylacetamide to arylthioacetamide with phosphorus (V) sulfide with following reduction of arylthioacetamide with complex sodium borohydride - nickel or cobalt chloride agents [7, 8]. Here we present a new short way route to N-methyltyramine and its ethers via the corresponding aryl-N-methylthioacetamides, shown at the scheme 1 at the example of N-methyltyramine and N,O-dimethyltyramine synthesis.