Naturalproductman’s Blog

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Archive for August, 2010

Mn-Catalyzed Chlorination

Posted by naturalproductman on August 31, 2010

John Groves and co-worker at Princeton have published in JACS on a manganese porphyrin mediated C-H chlorination reaction using sodium hypochlorite as the chlorine source.  The yields and regioselectivity are modest for the more complex systems but it’s cool nonetheless.

sodium hypochlorite

JACS paper

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Posted in C-H activation, Manganese, Methodology, Transition Metal | Leave a Comment »

DBU Mediated Cyclization

Posted by naturalproductman on August 31, 2010

Rachid Baati and co-workers at CNRS have published in Tetrahedron on a method to synthesize cyclohexnones starting from a beta-ketoester.

DBU

Tetrahedron paper

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

Rhenium Catalyzed Approach to Aminoindanes

Posted by naturalproductman on August 30, 2010

Kazuhiko Takai and co-workers at Okayama University have published in Organic Letters on a rhenium catalyzed cyclization reaction between an arylimin and allene to form amino-indanes.

rhenium


OL paper

Posted in Cascade Reactions, Methodology, Rhenium, Ring forming, Transition Metal | Leave a Comment »

Monanchocidin

Posted by naturalproductman on August 30, 2010

Tatyana Makarieva and co-workers at the Far-East Branch of the Russian Academy of Sciences have published in Organic Letters on the isolation of monanchocidin.  This guanidine alkaloid from the Far-Eastern sponge Monanchora pulchra had IC50 values of 5.1, 11.8 and 12.3 micromolar against human leukemia THP-1, human cervix epithelioid carcinoma HeLa, and mouse epidermal JB6 Cl41, respectively.

monanchocidin


OL paper

Posted in Alkaloids | Leave a Comment »

Carbonylative Heck

Posted by naturalproductman on August 30, 2010

Erik Alexanian and co-worker at the University of North Carolina at Chapel Hill have published in JACS on a carbonylative Heck reaction using palladium tetrakis(triphenyl)phosphine as the catalyst.  This reaction works best with non-polar solvents such as toluene because of a possible formation of phosphonium salts in polar solvents (THF:ACN).

palladium


JACS paper

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

Oxidative Prins-Pinacol

Posted by naturalproductman on August 28, 2010

Sylvain Canesi and co-workers have published in Chemistry a European Journal on an oxidative Prins-Pinacol rearrangement to access the 5,6-spirobicyclic portion of platensimycin.

hypervalent iodine

Chemistry – A European Journal paper

Posted in Antibiotics, Cascade Reactions, Hypervalent Iodine, Methodology, Named Reactions, Pinacol rearrangement, Prins, Spirocyclic centers | Leave a Comment »

Hydration/Alkylation/Fluorination of Alkynes

Posted by naturalproductman on August 27, 2010

Bo Xu and co-workers at the University of Louisville have published in ACIEE on a multicomponent approach to synthesize alpha-fluoro ketones – basically a hydration of an alkyne in addition to alkylating and fluorinating.

fluoro

ACIEE paper

Posted in Cascade Reactions, Gold, Methodology, Multi-Component Coupling, Transition Metal | Leave a Comment »

Asymmetric Iodolactonization

Posted by naturalproductman on August 27, 2010

Eric Jacobsen and co-worker have published in ACIEE on a urea catalyzed intramolecular iodolactonization reaction of an alkene.

iodolactonization

ACIEE paper

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

1,2-Addition/Oxy-Cope

Posted by naturalproductman on August 27, 2010

Jeremy Wulff and co-workers at the University of Victoria have published in Organic Letters on a tandem 1,2-addition/oxy-Cope reaction to access a bicyclic sulfone.

bicyclic sulfone

OL paper

Posted in Cascade Reactions, Methodology, Named Reactions, oxy-Cope rearrangement, Pericyclic reactions, Ring forming, Sigmatropic Rearrangements | Leave a Comment »

Synthesis of Rhazinilam

Posted by naturalproductman on August 27, 2010

Armen Zakarian and co-worker have published in UCSB on a Heck cyclization approach to access rhazinilam.

Heck

OL paper

Posted in Alkaloids, Asymmetric, Axial Chirality, cross coupling, Heck, Methodology, Palladium, Transition Metal | Leave a Comment »