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Synthèse totale énantiosélective de la (11R)-(-)-8-épi-11-hydroxy-aphidicoline par réactions de Diels-Alder/aldol transannulaires en tandem
(Université de Sherbrooke, 1999)
Au cours de cette thèse, nous verrons la synthèse totale de la (11R )-(-)-8-épi-11-hydroxy-aphidicoline et toutes les recherches pour y arriver. Le présent ouvrage sera divisé en quatre grandes parties. Dans un premier ...
Intramolecular additions of various π-nucleophiles to chemoselectively activated amides and application to the synthesis of (±)-tashiromine
(2006)
Abstract: Vilsmeier-Haack type cyclizations proved to be particularly efficient for generating parts of the polycyclic
cores of many alkaloids, although only monocyclizations have so far been reported. With the goal ...
Effect of substitution on the intramolecular 1,3-dipolar cycloaddition of alkene tethered münchnones
(2007)
Abstract: A sequence of chemoselective activation of N-acylaminoacids, münchnone generation, intramolecular 1,3-dipolar cycloaddition, and ring opening efficiently generated functionalized polycyclic structures such as ...
Synthesis of the tricyclic core of alkaloid securinol B using a cascade of vilsmeier-haack and mannich cyclizations
(2008)
Abstract: The Securinega alkaloids are a family of approximately 20 tetracyclic compounds isolated from diverse Securinega, Phyllanthus, and Margaritaria species of the Euphorbiaceae plant family. Most of these alkaloids ...
Highly chemoselective formation of aldehyde enamines under very mild reaction conditions
(2006)
Abstract: Although ketone enamines are widely used in organic synthesis, aldehyde enamines are rarely employed due to the limitations of their preparation using known methods (need for acid or base, excess of amine, and/or ...
Addition of tethered nonaromatic carbon nucleophiles to chemoselectively activated amides
(2005)
Abstract: In an effort to develop new ways of synthesizing polycyclic alkaloids, we successfully added silyl enol ethers, allylsilanes, and enamines to
iminium ions generated from amides. Because of their higher oxidation ...
Highly diastereoselective synthesis of substituted pyrrolidines using a sequence of azomethine ylide cycloaddition and nucleophilic cyclization
(2010)
Abstract: Although cycloadditions of azomethine ylides usually give mixtures of endo/exo adducts, we successfully tuned the mechanistic path of a new reaction cascade to afford substituted pyrrolidines in high yields and ...
A Versatile cascade of intramolecular vilsmeier-haack and azomethine ylide 1,3-dipolar cycloaddition toward tricyclic cores of alkaloids
(2008)
Abstract: In the pursuit of synthetic efficiency, we developed an innovative one-pot transformation of linear substrates into bi- and tricyclic adducts using a
cascade of amide activation, nucleophilic cyclization, ...
Synthesis of the tetracyclic core of daphnilactone B-type and yuzurimine-type alkaloid
(2011)
Abstract: The core of daphnilactone B-type and yuzurimine-type alkaloids was synthesized in only 16 steps from a known β-allyl-γ-butyrolactone. The key sequence of Vilsmeier–Haack cyclization and intramolecular azomethine ...
Competition between alkenes in intramolecular ketene-alkene [2 + 2] cycloaddition: What does it take to win?
(2005)
Abstract: In the course of developing a new synthetic methodology using ketenes in sequential cycloaddition steps, we were faced with a competition problem with molecules containing a ketene tethered to more than one ...