ACS Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 17837 - 17849
Published: Nov. 18, 2024
The investigation into the synthesis of azabicyclo[3.1.1]heptanes (azaBCHeps) as bioisosteres to flat aza-aromatics has garnered increasing attention, while it encounters significant challenges. Herein, we have demonstrated In(OTf)3-catalyzed (3 + 3) dipolar cyclization bicyclo[1.1.0]butanes (BCBs) with hydrazones and π-allyl-iridium 1,3-dipoles, engendering a diverse array azaBCHeps. BCBs furnished densely substituted 2,3-diazabicyclo[3.1.1]heptanes 2,3-diazabicyclo[3.1.1]heptenes under nitrogen oxygen atmospheres, respectively. A combination experimental computational investigations lends robust support for proton-transfer-interposed sequential mechanism. More importantly, by integrating In(OTf)3/iridium relay catalysis, enantiopure 2-azabicyclo[3.1.1]heptanes were constructed through aza-π-allyl-iridium in situ generated from N-allyl carbonates. Both methodologies exhibit mild reaction conditions good tolerance various functional groups. Moreover, copious derivatization products highlights utility newly synthesized heterobicyclic motifs versatile building blocks synthetic chemistry.
Language: Английский