The selectivities of nucleophilic substitution reactions of tetrahydropyran acetals promoted by trimethylsilyl trifluoromethanesulfonate depend upon the reaction solvent. Polar solvents favor the formation of S(N)1 products, while nonpolar solvents favor S(N)2 products. Trichloroethylene was identified as the solvent most likely to give S(N)2 products in both C- and O-glycosylation reactions.

'The development of a new, direct method for the preparation of dibenzo[a,e]cycloocta-1,5-dienes from phenylacetaldehyde by a double ortho Friedel-Crafts alkylation is described. When benzaldehyde (2b) is treated with trimethylsilyl iodide (3), a,n-diiodotoluene (6) is formed in high yield via the intermediacy of a-iodobenzyl trimethylsilyl ether (4b). Treatment of phenylacetaldehyde (%a) with ...

The [3+2]-cycloaddition of (trimethylsilyl)diazomethane (7) with 9H-fluorene-9-thione (1) at –60°C yields the spirocyclic 2,5-dihydro-5-trimethylsilyl-1,3,4-thiadiazole 10, which eliminates nitrogen at room temperature to give the 1,4-dithiane derivative 13 by dimerization of the intermediate fluorenethione (trimethylsilyl)methanide (11). This thiocarbonyl ylide can be trapped by 1 to give the ...

In the presence of magnesium and hexamethylphosphorictriamide, HMPT, trimethylchlorosilane, TMS-C1, reacts with cyanoepoxides to give related compounds. Ring cleavage at ? - position of cyanoepoxide, 1, followed by the addition of two trimethylsilyl groups leads to 2 then substitution of OSiMei by trimethylsilyl or H takes place to give ?, ? - bis (trimethylsilyl) nitrile or ? - trimethyls...

in order to detect hydrogen cyanide gene and to determine pseudomonas fluorescent efficiency in producing hydrogen cyanide for controlling the growth of rhizoctonia solanipathogen (the causal agent of sugar beet root and crown rot), samples were collected from sugar beet rhizosphere in sabzevar fields. after soil sampling and purification, 31 pseudomonas spp. isolates were separated on specific...

Diazo(trimethylsilyl)methylmagnesium bromide readily reacted with various ketones and aldehydes to give the corresponding 2-diazo-(2-trimethylsilyl)ethanols. These were efficiently converted to indazoles bearing hydroxymethyl units at the 3-position by intermolecular [3 + 2] cycloaddition with benzynes.

Hydrothermal reactions of a lead(II) salt with 3-aminopyrazine-2-carboxylic acid (HL1) gave rise to a series of lead(II) coordination compounds (1–6) having zero, one, two and three dimensional structures. X-ray diffraction structural analyses reveal that complexes [Pb(L1)2]2 (1) and [Pb(L1)(OCHNH2)(η-OCHO)]2 (2) possess dinuclear structures, containing a centre of symmetry. Complexes [Pb2(L1)4...