Diastereoselectivity Switch During Alkene Reductions: Diastereodivergent Syntheses of Molecular Fossils via MHAT or Homogeneous Catalytic Hydrogenation Reactions

Autor(es)

Maior, Christian R. S. ; Costa, Paulo C. S. ; Ligiero, Carolina B. P. ; Moraes, Lygia de S. ; Sousa, Gustavo R. ; Lima, Sidney G. ; Esteves, Pierre M. ; Miranda, Paulo C. M. L.

• Tipo de documento: Artigo Científico
• Fonte: CHEMISTRY-A EUROPEAN JOURNAL; v. 29, n. 20, p. 11-pg., 2023-03-06.

Resumo

Sixteen geosterane derivatives were synthesized in up to 57 % overall yields in four steps harnessing the olefin cross-metathesis (OCM) and Metal hydride H atom transfer (MHAT) or homogeneous hydrogenation reactions as key steps. Drawing on this strategy, the diastereomeric ratio (d. r.) reached up to 24 : 1 for the thermodynamic isomer and 7 : 1 for the other isomer in the hydrogenation step. In a geological sample from northeast Brazil, we confirmed the putative structures previously assumed as methyl 2-(3 alpha-5 alpha H-cholestan) acetate, methyl 2-(3 beta-5 alpha H-cholestan)acetate, and methyl 6-(3 beta-5 alpha H-cholestan)hexanoate, as well three new molecular fossils of approximately 120 million years old. We also proved the migration marking ability of those carboxylic acids derived from forerunner geosteranes during an oil migration event, which suggests their aptitudes as molecular odometers. Our approach demonstrated swiftness and effectiveness in preparing a molecular library of geological biomarkers would also be appropriate to generate stereochemical diversity in molecular libraries for medicinal chemistry and natural product anticipation. (AU)

• Processo FAPESP: 14/25770-6 - Novas fronteiras em reações de acoplamento cruzado mediadas por paládio: associando catálise enantiosseletiva, ativações C-H, novos materiais e reações em fluxo visando alta eficiência e sustentabilidade em processos sintéticos
• Beneficiário: Carlos Roque Duarte Correia
• Modalidade de apoio: Auxílio à Pesquisa - Temático