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Archive for the ‘Conia-Ene’ Category

Gomerone C synthesis

Posted by naturalproductman on November 16, 2012

Erick Carreira and co-worker have reported in ACIE on the synthesis of gomerone C.

gomerone C

ACIE paper

Posted in Cascade Reactions, Conia-Ene, Methodology, Named Reactions, Seven-Membered Rings, Total Synthesis | Leave a Comment »

Ag/La mediated Conia-ene

Posted by naturalproductman on June 7, 2011

Masakatsu Shibasaki and co-workers at the University of Tokyo have reported in ACIEE on a silver/lanthanum catalyzed Conia-ene reaction.

Conia-ene

ACIEE paper

Posted in Cascade Reactions, Conia-Ene, Lanthanides, Methodology, Named Reactions, Silver, Transition Metal | Leave a Comment »

Copper/amine cooperative catalysis

Posted by naturalproductman on May 26, 2011

Veronique Michelet and co-workers from CNRS have reported in the European Journal of Organic Chemistry on a copper/amine cooperative catalyzed Conia-ene type reaction.

looks like

European JOC paper

Posted in Cascade Reactions, Conia-Ene, Copper, Methodology, Named Reactions, Organocatalytic, Transition Metal | Leave a Comment »

A Cool Cascade

Posted by naturalproductman on January 10, 2011

Chi-Sing Lee and co-workers at Peking University have published in Organic Letters on a cascade reaction that leads to 5,6-bicyclic rings.  This reaction catalyzed by zinc (II) bromide involves a Diels-Alder reaction followed by a reaction that looks like the Conia-ene reaction.

bicycles

 

OL paper

Posted in Cascade Reactions, Conia-Ene, Cycloaddition, Diels-Alder, Methodology, Named Reactions, Pericyclic reactions, Transition Metal, Zinc | Leave a Comment »

Zn/Yb-Mediated Conia-Ene Reaction

Posted by naturalproductman on August 17, 2010

Jin-Heng Li and co-workers from Hunan Normal University have published in Synthesis on a Conia-ene reaction using Yb and Zn.  This reaction is catalytic in zinc but stoichiometric in ytterbium.  When a terminal alkyne is used, the cyclization is in the exo-dig mode, but when an internal alkyne is used, the cyclization is in the endo-dig mode.

Conia-Ene

Synthesis paper

Posted in Cascade Reactions, Conia-Ene, Methodology, Named Reactions, Ring forming, Transition Metal, Ytterbium, Zinc | Leave a Comment »

Indium-Catalyzed Cyclization

Posted by naturalproductman on May 12, 2010

Virginie Ratovelomanana-Vidal and co-workers at Chimie ParisTech have published in Organic Letters on what looks like an indium promoted Conia-Ene cyclization.

indium

OL paper

Posted in Cascade Reactions, Conia-Ene, Cooperative Catalysis, Methodology, Named Reactions, Ring forming | Leave a Comment »

A Michael/Conia-ene Cascade Reaction

Posted by naturalproductman on December 23, 2009

There are a lot of biologically active compounds out there with 5,7-bicyclic ring systems and because of these compounds exist, many different approaches for obtaining 5,7-ring systems are attempted.  Chi-Sing Lee and co-workers at Peking UniVersity Shenzhen Graduate School have recently published in Organic Letters on the synthesis of clavukerin A, a natural product that possesses this 5,7-bicyclic ring system.  The carbon skeleton is interesting, but I have to admit that the new reaction that was developed is even more interesting!  The starting substrate is an alpha,beta-ketone activated with an electron withdrawing group on the alpha position with an alkyne and an aldehyde.  Basically, they use a secondary amine (diethylamine) to do some enamine chemistry – specifically, a Michael addition of the aldehyde onto the enone and then with the presence of zinc (II) iodide, a Conia-ene reaction occurs to form the five membered ring.

michael conia ene


OL paper

Posted in Cascade Reactions, Conia-Ene, Conjugate Additions, Methodology, Ring forming, Transition Metal | Leave a Comment »

 
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