Enantioselective PCCP Brønsted acid-catalyzed aminalization of aldehydes

• Martin Kamlar,
• Robert Reiberger,
• Martin Nigríni,
• Ivana Císařová and
• Jan Veselý

Beilstein J. Org. Chem. 2021, 17, 2433–2440, doi:10.3762/bjoc.17.160

• stereogenic carbon center with good enantioselectivity (ee up to 80%) and excellent yields (up to 97%). Keywords: aminalization; Brønsted acid; organocatalysis; PCCP; pentacarboxycyclopentadiene; Introduction Nitrogen-containing heterocyclic compounds are commonly occurring in nature and constitute the core

• employed as catalysts in asymmetric dihydroquinazolinone synthesis [18]. Regarding the above-mentioned strategies involving chiral Brønsted acids, we envisioned that chiral pentacarboxycyclopentadiene (PCCP) derivatives could be used in the enantioselective aminalization of aldehydes with anthranilamide

Enantioselective PCCP Brønsted acid-catalyzed aza-Piancatelli rearrangement

• Gabrielle R. Hammersley,
• Meghan F. Nichol,
• Helena C. Steffens,
• Jose M. Delgado,
• Gesine K. Veits and
• Javier Read de Alaniz

Beilstein J. Org. Chem. 2019, 15, 1569–1574, doi:10.3762/bjoc.15.160

• rearrangement has been developed using a chiral Brønsted acid based on pentacarboxycyclopentadiene (PCCP). This reaction provides rapid access to valuable chiral 4-amino-2-cyclopentenone building blocks from readily available starting material and is operationally simple. Keywords: aza-Piancatelli; Brønsted

• aza-Piancatelli reaction, we sought to identify other asymmetric catalytic systems capable of controlling the absolute stereochemistry. To this end, we envisioned that the chiral pentacarboxycyclopentadiene (PCCP) Brønsted acid catalyst (8) recently developed by the Lambert lab might be suitable