Replacement of protons by deuterons in the glassing solvents led to 2-3-fold improvement of the (13)C dynamic nuclear polarization (DNP) solid-state NMR signal for samples doped with large electron spin resonance (ESR) linewidth free radicals galvinoxyl, DPPH, and 4-oxo-TEMPO. Meanwhile, the reverse effect is observed for (13)C DNP using small ESR linewidth free radicals BDPA and trityl OX063.

The asymmetric unit of the title compound, C26H28O6·2CH3OH, contains two independent methyl 6-O-trityl-α-d-gluco-pyran-oside mol-ecules and four methanol solvent mol-ecules. The rings of two methyl α-d-gluco-pyran-oside adopt chair conformations. In the crystal, extensive intra- and inter-molecular O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular archi...

A new method for the preparation of S-trityl(i.e. triphenylmethyl) and S-diphenylmethyl-cysteines or -cysteine peptides involves treatment of cysteine or cysteine peptides with aralkylcarbinols in the presence of trifluoroacetic acid or hydrogen halides in acetic acid solution. The optimal conditions for the removal of these S-protecting aralkyl groups by trifluoroacetic acid or hydrogen halide...

The synthesis of four new peptidyl nucleosides is reported. The kinetic data obtained for the transesterification of 2'/3'-O-benzyloxycarbonyl-L-p-nitrophenylalanyl 5'-O-trityl ribonucleosides which contain different substituents at C position of the purine residue indicates for different mechanisms of the transesterification reaction. The peptidyl nucleosides with an amino group at C position ...

Microwave-assisted unimolecular isomerization-Claisen domino reactions of 1,3-di(hetero)aryl propargyl trityl ethers lead, depending on the basicity of the amine, either to the formation of tricyclo[3.2.1.0(2,7)]oct-3-enes (with triethylamine) or to indanes (with DBU). Based upon product analyses and computations, this base dependent dichotomy can be rationalized as a sequel of pericyclic react...

Using selected theoretical methods the affinity of a large range of Lewis bases towards model cations has been quantified. The range of model cations includes the methyl cation as the smallest carbon-centered electrophile, the benzhydryl and trityl cations as models for electrophilic substrates encountered in Lewis base-catalyzed synthetic procedures, and the acetyl cation as a substrate model ...

The synthesis and characterization of a novel trityl-TEMPO biradical and the investigation of its properties as Dynamic Nuclear Polarization (DNP) polarizing agent are reported. Comparison with a structurally related monoradical (PTM-TEMPE) or mixtures of the two monoradical components reveals that the biradical has a much higher polarization efficiency and a faster polarization buildup. This o...

A diazole is N-substituted with 1-trityl-2-methylaziridine and demethylated and oxidised with NBS under acidic conditions to give a benzimidazolequinone; this novel anti-tumour agent is marginally more cytotoxic than mitomycin C (MMC) towards the normal human fibroblast cell line GM00637, while the MMC-hypersensitive human Fanconi anaemia (FA) cell line, PD20i, lacking the FANCD2 protein, is al...