RESUMO
An atropo-diastereoselective synthesis with dr up to 98/2 towards the biaryl subunit of vancomycin based on the use of enantiopure ß-hydroxysulfoxide derivatives as novel chiral auxiliary is reported.
Assuntos
Vancomicina/química , Estrutura Molecular , Estereoisomerismo , Vancomicina/análogos & derivadosRESUMO
Through iterative design cycles we have discovered a number of novel new classes where the imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepine was deemed the most promising GABA(A) alpha5 inverse agonist class with potential for cognitive enhancement. This class combines a modest subtype binding selectivity with inverse agonism and has the most favourable molecular properties for further lead optimisation towards a central nervous system (CNS) acting medicine.
Assuntos
Benzodiazepinas/química , Nootrópicos/química , Receptores de GABA-A/metabolismo , Triazóis/química , Animais , Benzodiazepinas/síntese química , Benzodiazepinas/farmacologia , Descoberta de Drogas , Agonismo Inverso de Drogas , Agonistas de Receptores de GABA-A , Humanos , Nootrópicos/síntese química , Nootrópicos/farmacologia , Oócitos/efeitos dos fármacos , Triazóis/síntese química , Triazóis/farmacologia , Xenopus laevisRESUMO
Highly atropo-diastereoselective Suzuki coupling between aryl halides bearing stereogenic benzylic carbinols with sulfoxide, thioether, or dimethylamino groups as efficient internal chelating ligands and 2-methoxy-1-naphthylboronic acid were performed with high yields; a palladacycle is proposed as a potential transition state. [reaction: see text]
RESUMO
The coupling reaction of pinacolborane with various aryl bromides in the presence of a catalytic amount of Pd(OAc)(2) together with DPEphos as ligand and Et(3)N as base provided arylboronates. High yields were obtained in the case of electron-donor substituted aryl bromides. The direct preparation of arylboronates allowed the one-pot, two-step synthesis of unsymmetrical biaryls in high yields. [reaction: see text]
RESUMO
[reaction: see text] Highly diastereoselective biaryl Suzuki coupling reactions of (1R)-1-(2-iodo or bromophenyl)-2-(R)-(4-tolylsulfinyl)-1-ethanol derivatives with various aryl- or naphthylboronic acids (or esters) were performed with high yields (up to 99%) and an excellent control of the axial chirality (up to 98% de).