RSS 1.0Sciences – Articles de périodiques
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Experimental evidence for spin-triplet states in Titanium implanted AlN film : an electron spin resonance study
(2023)Abstract : Spin carrying defects in wide-bandgap semiconductors are promising candidates for the development of quantum information and quantum sensing technology. Here we report experimental evidence for the formation of ... -
DNA-damaging agents induce the RecA-independent homologous recombination functions of integrating conjugative elements of the SXT/R391 family
(2013)Abstract : Integrating conjugative elements (ICEs) of the SXT/R391 family are major contributors to the spread of antibiotic resistance genes. These elements also catalyze their own diversity by promoting inter-ICE ... -
Functionalized polyhydroquinolines from amino acids using a key one-pot cyclization cascade and application to the synthesis of (±)-Δ7-mesembrenone
(2021)Substituted polyhydroquinolines are ubiquitous skeletal cores found in drugs and bioactive natural products. As a new route to access this motif, we successfully developed a one-pot cyclization cascade with high chemocontrol ... -
Mapping ecosystem services provided by wetlands at multiple spatiotemporal scales : a case study in Quebec, Canada
(2019)Abstract : Wetlands are affected by climate and anthropogenic changes, which influence the ecosystem services (ES) they provide. This study presents a spatially explicit quantification of wetland ESs. The study site is the ... -
Crop scouting using UAV imagery : a case study for potatoes
(2020)Abstract : Crop scouting is essential to manage crops such as potatoes and detect stresses. In fact, conventional approaches require a lot of time and staff. The rise of unmanned aerial vehicle (UAV) imagery offers interesting ... -
Sequential One-pot Vilsmeier–Haack and organocatalyzed Mannich cyclizations to functionalized benzoindolizidines and benzoquinolizidines
(2020)Abstract: The development of new one-pot sequential cyclizations involving a Vilsmeier–Haack reaction followed by an organocatalyzed Mannich reaction is reported. This synthetic strategy gives access to functionalized ... -
Rapid assembly of quinolizidines via consecutive nucleophilic cyclizations onto activated amides
(2011)Abstract: A new approach to the synthesis of quinolizidines involving a cascade of nucleophilic cyclizations triggered by chemoselective amide activation is reported. Particular attention was given to the effect of the ... -
Short approach toward the nonracemic A,B,E tricyclic core of calyciphylline B-type alkaloids
(2017)Abstract: A suitably functionalized tricyclic adduct containing the common A,B,E rings found in calyciphylline B-type alkaloids was obtained in nine linear steps. The key transformation features an efficient one-pot sequence ... -
General approach toward aspidospermatan-type alkaloids using one-pot Vilsmeier–Haack cyclization and azomethine ylide cycloaddition
(2017)Abstract: The development of a new one-pot reaction sequence afforded the tricyclic core of several aspidospermatan-type alkaloids from a linear, densely functionalized substrate. The key sequence features a highly ... -
Bis-michael acceptors as novel probes to study the Keap1/Nrf2/ARE pathway
Other titre : Supporting information for "Bis-michael acceptors as novel probes to study the Keap1/Nrf2/ARE pathway"(2016)Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator that promotes the transcription of cytoprotective genes in response to oxidative/electrophilic stress. Various Michael-type compounds were designed ... -
Studies toward total synthesis of (±)-caldaphnidine C via one-pot sequential intramolecular Vilsmeier–Haack and azomethine ylide 1,3-dipolar cycloaddition
(2016)An application of a one-pot sequential Vilsmeier–Haack cyclization and intramolecular azomethine ylide 1,3-dipolar cycloaddition toward the total synthesis of (±)-caldaphnidine C is presented. It allowed an efficient ... -
Preparation of conformationally restricted β2,2- and β2,2,3-amino esters and derivatives containing an all-carbon quaternary center
(2015)Abstract: β-Amino acids are routinely incorporated into peptidic drugs to increase their stability and to incur conformational biases. However, the synthesis of highly substituted β-amino acids still represents a great ... -
Asymmetric total synthesis of (+)-virosine a via sequential nucleophilic cyclizations onto an activated formamide
(2012)Abstract: The first synthesis of tetracyclic alkaloid virosine A is reported. The natural alkaloid was prepared in only 13 steps, in an enantioenriched form. The azabicyclo[2.2.2]octane core was efficiently assembled using ... -
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 ... -
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 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 ... -
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 ... -
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 ... -
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 ...
