Lewis Acid-Catalyzed Strain-Enabled (3+3) Annulation of Bicyclo[1.1.0]Butanes With Indolylalcohols: Synthesis of Indole-Fused Aza-Bicyclo[3.1.1]Heptanes.
- 1Department of Chemistry, Indian Institute of Technology, New Delhi, India.
- 2Centre For Nano and Material Sciences, Jain (Deemed-to-be University), Bangalore, Karnataka, India.
Abstract
Strain release has long inspired the discovery of unique reactivity, enabling diverse synthetically valuable transformations. Bicyclo[1.1.0]butanes (BCBs), due to their high ring strain, have emerged as versatile building blocks for constructing complex bicyclic architectures. Herein, we report a Lewis acid-catalyzed formal (3 + 3) annulation of BCBs with indolyl alcohols, providing rapid access to indole-fused aza-bicyclo[3.1.1]heptanes. The reaction proceeds under mild conditions, tolerates a broad range of functional groups, and delivers rigid, sp³-rich scaffolds efficiently. Mechanistic studies, including control experiments and computational analysis, indicate a stepwise pathway in which Lewis acid activation of indolyl alcohols generates reactive intermediates, while strain-release of BCBs drives C-C bond formation, followed by C-N bond formation via ring expansion to furnish the fused Aza-bicyclic products.
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BibTeX
@article{dey2026lewis,
title = {{Lewis Acid-Catalyzed Strain-Enabled (3+3) Annulation of Bicyclo[1.1.0]Butanes With Indolylalcohols: Synthesis of Indole-Fused Aza-Bicyclo[3.1.1]Heptanes.}},
author = {Mainak Dey and Tuhin Subhra Das Mahapatra and Pragya Sharma and Manoj V Mane and Chinmoy Kumar Hazra},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
year = {2026},
month = oct,
doi = {10.1002/advs.78354},
url = {https://europepmc.org/article/MED/42893481},
note = {CC BY},
}
RIS
TY - JOUR
TI - Lewis Acid-Catalyzed Strain-Enabled (3+3) Annulation of Bicyclo[1.1.0]Butanes With Indolylalcohols: Synthesis of Indole-Fused Aza-Bicyclo[3.1.1]Heptanes.
AU - Mainak Dey
AU - Tuhin Subhra Das Mahapatra
AU - Pragya Sharma
AU - Manoj V Mane
AU - Chinmoy Kumar Hazra
PY - 2026
DA - 2026/10/18
JO - Advanced science (Weinheim, Baden-Wurttemberg, Germany)
DO - 10.1002/advs.78354
UR - https://europepmc.org/article/MED/42893481
AB - Strain release has long inspired the discovery of unique reactivity, enabling diverse synthetically valuable transformations. Bicyclo[1.1.0]butanes (BCBs), due to their high ring strain, have emerged as versatile building blocks for constructing complex bicyclic architectures. Herein, we report a Lewis acid-catalyzed formal (3 + 3) annulation of BCBs with indolyl alcohols, providing rapid access to indole-fused aza-bicyclo[3.1.1]heptanes. The reaction proceeds under mild conditions, tolerates a broad range of functional groups, and delivers rigid, sp³-rich scaffolds efficiently. Mechanistic studies, including control experiments and computational analysis, indicate a stepwise pathway in which Lewis acid activation of indolyl alcohols generates reactive intermediates, while strain-release of BCBs drives C-C bond formation, followed by C-N bond formation via ring expansion to furnish the fused Aza-bicyclic products.
SN - 2198-3844
ER -