New insight into nucleo α-amino acids - Synthesis and SAR studies on cytotoxic activity of β-pyrimidine alanines.

Three series of the β-pyrimidine alanines, including willardiine - a naturally occurring amino acid, were prepared from the l-serine-derived sulfamidates. Compounds 3b, 4a and 4b demonstrated antiproliferative activity toward the studied cancer cell lines, albeit the effect of these compounds on human brain astrocytoma MOG-G-CCM cells was more significant than on human neuroblastoma SK-N-AS cells. The cytosine analog of willardiine, compound 4b, reduced viability of MOG-G-CCM cells with EC = 36 ± 2 μM, more effectively than AMPA antagonist GYKI 52466.

A fine-tuned molybdenum hexacarbonyl/phenol initiator for alkyne metathesis.

A new, highly potent activator for molybdenum hexacarbonyl and 2-fluorophenol is described. An "instant"catalyst formed in situ from molybdenum hexacarbonyl and 2-fluorophenol shows high activity for cross- and ring-closing alkyne metathesis reaction. The use of 2-fluorophenol can be combined with other activation methods to allow alkyne metathesis at relatively low temperature (80 degrees C).

An improved catalyst for ring-closing alkyne metathesis based on molybdenum hexacarbonyl/2-fluorophenol.

[reaction: see text] An improved "instant" catalyst for ring-closing alkyne metathesis reaction is described. Catalyst formed in situ from molybdenum hexacarbonyl and 2-fluorophenol can be used without exclusion of air and moisture and shows high activity in metathesis of functionalized diynes. This system allows cyclization of substrates which were incompatible with previously known Mo(CO)(6)/phenol catalysts.