Selective syntheses are now available for compounds of many classes, based on C-centered radicals, exploiting a diverse range of mechanisms. The prospect for chemistry based around N- and O-centered radicals is probably more favorable because of the importance of heterocycles as biologically active materials. Heteroradical chemistry is still comparatively underdeveloped due to the need for safe...

Leontidine and camoensine, the main representatives of small quinolizidine-indolizidine alkaloid subgroup, are characterized by an inner bispidine system to which a 2-pyridone pyrrolidine fused on opposite sides. We efficiently synthesized both natural products from commercially available abundant cytisine, was converted into key intermediate, N-Boc-11-oxocytisine, iodine oxidation protection. ...

Oxazolo[5,4-f]quinoxalines, thiazolo[5,4-f]quinoxalines and pyrazino[b,e]isatins were all obtained from 5-iodo-6-aminoquinoxalines. While the first two families synthesized by nitrogen functionalization subsequent copper-catalyzed cyclization, latter was Sonogashira coupling, alkyne hydration, oxidative cyclization. Most of polycycles evaluated in biological tests.

A ring-closing alkene metathesis (RCM)/ oxyselenation-selenoxide elimination sequence was established to the sodium salts E- and Z-25 of the originally proposed structure for the recently isolated cytotoxin aruncin B (1), as well as to the sodium salt Z-34 of a related ethyl ether regioisomer; however, none of their corresponding free acids could be obtained. Their acid sensitivity, together wi...

The cycloisomerisation of simple keto-alkynes proceeds at room temperature under the mild conditions of gold catalysis. Bicyclic fused and spiro compounds can be obtained by overall 5-exo and 6-exo carbon-carbon bond-forming cyclisations.

Exosomes derived from cancer cells can affect various functions of mesenchymal stem cells (MSCs) via conveying microRNAs (miRs). miR-21 and miR-146a have been demonstrated to regulate MSC proliferation and transformation. Interleukin-6 (IL-6) secreted from transformed MSCs in turn favors the survival of multiple myeloma (MM) cells. However, the effects of MM exosomes on MSC functions remain lar...

The reaction of furylacrylic acid with cyclopentadiene in toluene gave the expected Diels-Alder endo-and exo-adductsin -1 : 1 ratio. The adducts were separated by iodolactonization method to provide 3-endo-(2'-furyl) bicyclo 12.2.11 hept-5-ene- 2-exo-carboxylic acid and 3-exo-(2'-fury1)bicyclo 12.2.11 hept-5-ene-2-endocarboxylic acid. Esterification of these acids by MeI / HMPA gave the exp...

A concise synthetic route has been developed for the preparation of a constrained peptidomimetic pyrazinone building block. From hydroxy-L-lysine, the desired pyrazinone is obtained in 43% overall yield (6 steps) via an efficient deprotection-double cyclization sequence.