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Updated: Sep 30, 2025

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
Concise syntheses of GB22, GB13, and himgaline by cross-coupling and complete reduction
Eleanor M Landwehr1, Meghan A Baker1, Takuya Oguma1
1Department of Chemistry, Scripps Research, La Jolla, CA, USA.
Abstract:
Neuroactive metabolites from the bark of Galbulimima belgraveana occur in variable distributions among trees and are not easily accessible through chemical synthesis because of elaborate bond networks and dense stereochemistry. Previous syntheses of complex congeners such as himgaline have relied on iterative, stepwise installation of multiple methine stereocenters. We decreased the synthetic burden of himgaline chemical space to nearly one-third of the prior best (7 to 9 versus 19 to 31 steps) by cross-coupling high fraction aromatic building blocks (high Fsp2) followed by complete, stereoselective reduction to high fraction sp3 products (high Fsp3). This short entry into Galbulimima alkaloid space should facilitate extensive chemical exploration and biological interrogation.
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