RESUMO
Diazo compounds play an important role as a coupling partner in the synthesis of unique π-conjugated 7-azaindole derivatives via rhodium(iii)-catalyzed double C-H activation/cyclization.
RESUMO
An efficient rhodium-catalyzed dehydrogenative Heck-type reaction between N-aryl-substituted 7-azaindoles and various alkenes through a H2 -releasing process without the need of any oxidizing agent was developed. The novel methodology broadens the scope of metal-catalyzed hydrogen-releasing reactions to include rhodium catalysis.
RESUMO
Rhodium(iii)-catalyzed N-directed ortho C-H activation and subsequent roll-over C-H activation represents an important strategy to synthesize fused polycyclic compounds. Herein, the novel methodology broadens the scope of the coupling partner to alkenes, which working smoothly with 7-azaindoles has been proven to be an efficient and atom-economical strategy to access complex π-conjugated 7-azaindole derivatives.
RESUMO
A novel one-pot synthesis of π-conjugated polycyclic compounds, which could undergo further facile transformation to form complex polycyclic heteroarene compounds, has been realized between 7-azaindoles and α,ß-unsaturated ketones. This distinctive cascade process proceeds via a rhodium(iii)-catalyzed alkylation/copper-catalyzed radical annulation-aromatization pathway.
RESUMO
We have successfully accomplished a catalytic asymmetric total synthesis of entecavir, a first-line antihepatitis B virus medication. The pivotal aspect of our strategy lies in the utilization of a Pd-catalyzed enyne borylative cyclization reaction, enabling the construction of a highly substituted cyclopentene scaffold with exceptional stereoselectivity. Additionally, we efficiently accessed the crucial 1,3-diol enyne system early in our synthetic route through a diarylprolinol organocatalyzed enantioselective cross-aldol reaction and Re-catalyzed allylic alcohol relocation. By strategically integrating these three catalytic protocols, we established a practical pathway for acquiring valuable densely heteroatom-substituted cyclopentene cores.
Assuntos
Antivirais , Ciclopentanos , Guanina , Vírus da Hepatite B , Ciclopentanos/química , Ciclopentanos/síntese química , Catálise , Antivirais/química , Antivirais/síntese química , Estereoisomerismo , Estrutura Molecular , Guanina/química , Guanina/análogos & derivados , Vírus da Hepatite B/efeitos dos fármacos , Ciclização , Paládio/químicaRESUMO
Development of efficient and stereoselective synthesis of prostaglandins (PGs) is of utmost importance, owing to their valuable medicinal applications and unique chemical structures. We report here a unified synthesis of PGs cloprostenol, bimatoprost, PGF2α, fluprostenol, and travoprost from the readily available dichloro-containing bicyclic ketone 6a guided by biocatalytic retrosynthesis, in 11-12 steps with 3.8-8.4% overall yields. An unprecedented Baeyer-Villiger monooxygenase (BVMO)-catalyzed stereoselective oxidation of 6a (99% ee), and a ketoreductase (KRED)-catalyzed diastereoselective reduction of enones 12 (87 : 13 to 99 : 1 dr) were utilized in combination for the first time to set the critical stereochemical configurations under mild conditions. Another key transformation was the copper(ii)-catalyzed regioselective p-phenylbenzoylation of the secondary alcohol of diol 10 (9.3 : 1 rr). This study not only provides an alternative route to the highly stereoselective synthesis of PGs, but also showcases the usefulness and great potential of biocatalysis in construction of complex molecules.
RESUMO
A convenient rhodium(III)-catalyzed cascade reaction of 7-azaindoles and alkynes through multiple C-H bond activation for the synthesis of unique [5]azahelicenes has been developed. The optical property of these screw-shaped helicene derivatives could be further utilized in electronic devices to recognize mercury ions.