Naturalproductman’s Blog

Hey, is that a natural product?!

Archive for the ‘Mechanistic’ Category

Evans enolate in solution

Posted by naturalproductman on October 5, 2015

David Collum and colleague have reported in JACS on the solution structure of an Evans enolate.
Evans

JACS paper

Advertisements

Posted in Computational, DFT, Mechanistic, Methodology | Leave a Comment »

Mechanistic study of the asymmetric Nazarov cyclization

Posted by naturalproductman on October 1, 2015

Kendall Houk and co-workers reported in JACS on a mechanistic investigation on a reaction discovered by Tius: the asymmetric Nazarov cyclization catalyzed by a thiourea-primary amine catalyst.

DFT

JACS paper

Posted in Computational, DFT, Mechanistic, Named Reactions, Nazarov cyclization | Leave a Comment »

Going from a diol to a tetrahydropyran in salinomycin

Posted by naturalproductman on September 25, 2015

Peter Leadlay and co-workers from the University of Cambridge have reported in ACIE on the enzyme that makes the tetrahydropyran ring in salinomycin. The tetrahydropyran is proposed to come from a diol where one of the hydroxy groups is in the beta-position to a ketone and subsequently dehydrates to form an enone. The enone undergoes an intramolecular Michael reaction to form the tetrahydropyran. However, when the reaction is done in vitro with the purified enzyme, they don’t see the enone intermediate, so I wonder if it is a processive reaction; in other words, the enone forms in the enzyme active site without being released and cyclizes to the tetrahydropyran.

salinomycin

ACIE paper

Posted in Biosynthesis, Chemical Biology, Enzymes, Mechanistic, Polyketides, Tetrahydropyran | Leave a Comment »

Triazoline + light

Posted by naturalproductman on September 4, 2015

Miguel Garcia-Garibay and co-workers at UCLA have reported in Organic Letters on a denitrogenation reaction of a triazoline using light to make an aziridine.
triazole
OL paper

Posted in Computational, Light Mediated, Mechanistic, Methodology | Leave a Comment »

Newman-Kwart reaction mechanism

Posted by naturalproductman on July 13, 2015

Hafize Ozcan and co-workers from Trakya University in Turkey have reported in Tetrahedron on an interesting mechanistic investigation of the Newman-Kwart reaction.

Newman-Kwart

Tetrahedron paper

Posted in Cascade Reactions, Computational, DFT, Electrocyclization, Mechanistic, Methodology, Named Reactions, Newman-Kwart, Sigmatropic Rearrangements | Leave a Comment »

α-Ketol rearrangement

Posted by naturalproductman on June 9, 2015

Ulrich Koert and co-workers from Philipps-University Marburg have reported in Organic Letters on an alpha-ketol rearrangment.They heat the reaction in a sealed tube to 70 degrees and the solvent is in DCM – with 2.5 mol equivalents of BF3 etherate, sounds a bit harsh – but nonetheless an interesting sigmatropic rearrangement.

 
ketol
OL paper

Posted in Cascade Reactions, Mechanistic, Methodology | Leave a Comment »

Sufur ylide chemistry – intramolecular cyclopropanation

Posted by naturalproductman on May 28, 2015

Nuno Maulide and co-workers from the University of Vienna have reported in JOC on an intramolecular cyclopropanation from a sulfur slide precursor and what follows is a nice mechanistic investigation.

sulfur

JOC paper

Posted in Computational, DFT, Gold, Mechanistic, Methodology, Transition Metal | Leave a Comment »

Domino acylation Diels-Alder

Posted by naturalproductman on May 2, 2015

Jeffrey Aube (University of Kansas) and Dean Tantillo (UC Davis) have teamed up to study the mechanism of a domino acylation-Diels Alder reaction.

domino

OL paper

Posted in DFT, Diels-Alder, Mechanistic, Methodology, Named Reactions | Leave a Comment »

Terpene cyclization involving carbons switching

Posted by naturalproductman on March 5, 2015

Tomohisa Kuzuyama and co-workers at the University of Tokyo have reported in ACIE on an mechanistically interesting terpene cyclization involving two carbons switching.

terpene

ACIE paper

Posted in Biosynthesis, Enzymes, Mechanistic, Proteins | Leave a Comment »

Sigmatropic rearrangements

Posted by naturalproductman on January 18, 2015

Matthew Cook and co-workers from Queen’s University Belfast in the UK have reported in JOC on some interesting sigmatropic reactions, depending on the base used, an isomerization Claisen occurs or a [2,3]-Wittig-anionic oxy-Cope rearrangement occurs.
rearrangement
JOC paper

Posted in Mechanistic, Methodology, Pericyclic reactions, Sigmatropic Rearrangements | Leave a Comment »