A short synthesis of (±)-tecomanine via a Pauson–Khand-based route
摘要:
The N-carboethoxy precursor to (+/-)-tecomanine has been prepared in 11 steps from 2-methyl-l-buten-3-yne. The key step, Pauson-Khand cyclization of a methylated 5-aza-6-nonen-1-yne succeeds, but only in low yield, a consequence of the dialkyl substitution about the azaenyne framework. Nevertheless, the overall sequence to that point is one of the more efficient to be described. (C) 2003 Elsevier Science Ltd. All rights reserved.
A short synthesis of (±)-tecomanine via a Pauson–Khand-based route
摘要:
The N-carboethoxy precursor to (+/-)-tecomanine has been prepared in 11 steps from 2-methyl-l-buten-3-yne. The key step, Pauson-Khand cyclization of a methylated 5-aza-6-nonen-1-yne succeeds, but only in low yield, a consequence of the dialkyl substitution about the azaenyne framework. Nevertheless, the overall sequence to that point is one of the more efficient to be described. (C) 2003 Elsevier Science Ltd. All rights reserved.
The reaction of secondary homopropargylamines, isocyanides, and water in the presence of a catalytic amount of silver acetate and subsequent purification by chromatography on silica gel afforded substituted proline amides in good to excellent yields. Primary homopropargylamines underwent a cyclizative Ugi–Joullié three-component reaction with isocyanides and carboxylic acids to afford functionalized