.png){kind=icon}
.png){kind=icon}
Return
Cycloisomerization/(2+1) Annulation of Enyne-Amide With α-Bromomalonate: A Novel and Selective Access to Oxa/Aza-Spiro[2.4]heptane Derivatives
.png){kind=icon}
PRE
AI
Y
Y
H
H
X
L
DOI：10.1002/ajoc.70471.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Oxa- and aza-spiro[2.4]heptane frameworks are privileged scaffolds in bioactive molecules. Herein, we report a catalyst-controlled divergent synthesis of these spirocycles from readily accessible enyne-amides and α-bromomalonates. Under Au(I) catalysis, cycloisomerization generates a furan-fused azadiene intermediate, which undergoes base-promoted (2+1) annulation to afford 5-oxa-spiro[2.4]heptanes with excellent diastereoselectivity (>20:1). In contrast, Pd(II) catalysis triggers an intramolecular hydroamination to form a pyrrole-fused oxodiene, followed by (2+1) annulation to deliver 5-aza-spiro[2.4]heptanes. This protocol enables selective assembly of diverse spirocyclic products under mild conditions, providing good to excellent yields with high diastereoselectivity.
Keywords:
aza-spiro[2.4]heptane
cyclopropanation
domino annulation
enyne-amide
oxa-spiro[2.4]heptane
Journal
IF:
2.7
Papers:
938
Citations:
6.5K
Organization
Cited Papers