Naturalproductman’s Blog

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Archive for December, 2010

Palladium cascade for pyrroles

Posted by naturalproductman on December 22, 2010

Trost and co-workers have published in JACS on a palladium catalyzed cascade reaction between a BOC-protected propargylamine and an alkyne to yield substituted pyrroles in a two step process.  Interestingly, the stoichiometry of the ligand, tris-(2,6-dimethoxyphenyl)phosphine (TDMPP), determines whether or not it yields the ynenoate product or the isopyrrole product – when equimolar amounts of ligand to Pd(OAc)2 were used, the product formation stopped at the ynenoate (non-cyclized) product, however, when they started decreasing the amount of ligand to Pd(OAc)2, they observed more and more isopyrrole (cyclized) product.

pyrroles

 

JACS paper

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Posted in Cascade Reactions, Methodology, Palladium, Transition Metal | Leave a Comment »

Salvileucalin Synthesis

Posted by naturalproductman on December 21, 2010

Well they did it – salvileucalin was synthesized by Reisman and co-workers.

salvileucalin

 

JACS paper

Posted in Carbene, Copper, Methodology, Named Reactions, retro-Claisen rearrangement, Transition Metal | Leave a Comment »

Platinum Carbene [3+2]

Posted by naturalproductman on December 21, 2010

Nobuharu Iwasawa and co-workers have published in JACS on a platinum catalyzed [3+2] cycloaddition between a platinum carbene and an enol ether.

3+2

 

JACS paper

Posted in Carbene, Cascade Reactions, Methodology, Platinum, Transition Metal | Leave a Comment »

Mitsunobu Reaction in an Sn2 Prime Context

Posted by naturalproductman on December 20, 2010

Kazuhiko Sakaguchi and co-workers at Osaka City University have published in Tetrahedron Letters on a Mitsunobu type anti-Sn2 prime reaction.

sn2 prime

 

TL paper

Posted in Cascade Reactions, Mechanistic, Methodology, Mitsunobu, Named Reactions, Sn2 prime | Leave a Comment »

Isomerization with Lawesson’s Reagent

Posted by naturalproductman on December 20, 2010

Lawesson’s reagent normally converts carbonyls to thiocarbonyls.  Emanuele Miserazzi and co-workers at GlaxoSmithKline in Italy have published in Tetrahedron Letters on a transposition of the oxidized atom in N-benzylpiperazinones when using Lawesson’s reagent.

transposition

 

TL paper

Posted in Lawesson's, Mechanistic, Methodology, Named Reagents | Leave a Comment »

Reveromycins

Posted by naturalproductman on December 18, 2010

Robert Capon and co-workers at Griffith University in Australia have published in Organic and Biomolecular Chemistry on the isolation and biological activities of reveromycins.

reveromycin

OBC paper

Posted in Cancer, Polyketides, Spiroketals | Leave a Comment »

GOAT Inhibitor

Posted by naturalproductman on December 17, 2010

Philip Cole and co-workers at Johns Hopkins University have published in Science on a ghrelin O-acyltransferase inhibitor, GO-CoA-Tat, a bisubstrate antagonist of GOAT, which is a peptide, so it is not a suitable drug – the body degrades peptides.

GOAT

Science paper

Posted in Diseases, ghrelin O-acyltransferase inhibitor, Obesity | Leave a Comment »

Ring Opening with DABCO

Posted by naturalproductman on December 17, 2010

William Miles and co-workers from Lafayett College have published in Synthesis on a DABCO catalyzed reaction that converts hydroxypyranones into acyclic triketones.

triketone

 

Synthesis paper

Posted in Cascade Reactions, Methodology, Organocatalytic, Ring Opening | Leave a Comment »

Formal Synthesis of Telomestatin

Posted by naturalproductman on December 17, 2010

Christopher Moody and co-workers at the University of Nottingham have published in JACS on a formal total synthesis of telomestatin.

telomestatin

JACS paper

Posted in Carbene, Cascade Reactions, Methodology, Oxazoles, Rhodium, telomerase, Transition Metal | Leave a Comment »

New Tricks with Grignard

Posted by naturalproductman on December 17, 2010

Chenzhong Cao and co-workers at Hunan University of Science and Technology have published in Organic Letters on a Grignard addition onto isopropenyl acetate to form 1,3-diols.

Grignard

 

OL paper

Posted in Cascade Reactions, Grignard, Methodology, Named Reactions | Leave a Comment »