Studies on intramolecular alkylation. XII. Stereochemical aspects of the preparation of β,γ-unsaturated aldehydes from the [2,3]-sigmatropic rearrangement of ammonium ylides

1980 ◽  
Vol 33 (7) ◽  
pp. 1559 ◽  
Author(s):  
LN Mander ◽  
JV Turner
Keyword(s):  
Bond Formation ◽  
Sigmatropic Rearrangement ◽  
Carbon Bond ◽  
Intramolecular Alkylation ◽  
Unsaturated Aldehydes ◽  
Excellent Yield ◽  
Carbon Carbon Bond ◽  
Diastereomeric Pair

The [2,3]-sigmatropic rearrangement of a series of acetonitrile-derived allylic ammonium ylides [RCH2N+ (C4H8)-CHCN; R = 4'-t- butylcyclohexylidenemethyl (3), 4'-t-butylcyclohex-1-enyl (10), 5'-t- butyl-2'-methylcyclohex-1-enyl (14), 4'-t-butyl-2'-methylcyclohex-1- enyl (20)], followed by acid-catalysed hydrolysis in each case, furnished an excellent yield of a diastereomeric pair of β,γ-olefinic aldehydes [(5)/(6), (12)/(13), (15)/(16) and (21)/(22)]. With cyclohexylidene ylide (4) addition of the carbanion to the more exposed (equatorial vector) face is strongly preferred. In the cyclohexenyl examples there is a clear stereoelectronic requirement in opposition to steric forces which leads mainly to axial carbon-carbon bond formation.

Palladium chloride catalyzed photochemical Heck reaction

2013 ◽  
Vol 91 (5) ◽  
pp. 348-351 ◽  
Author(s):  
Suresh B. Waghmode ◽  
Sudhir S. Arbuj ◽  
Bina N. Wani ◽  
C.S. Gopinath
Keyword(s):  
Visible Light ◽  
Heck Reaction ◽  
Palladium Nanoparticles ◽  
Bond Formation ◽  
Aryl Halides ◽  
Palladium Chloride ◽  
Carbon Bond ◽  
Excellent Yield ◽  
Carbon Carbon Bond ◽  
Uv Visible

PdCl2 catalyzed carbon–carbon bond formation (Heck reaction) between substituted aryl halides and olefins was carried out without a ligand, under irradiation with UV–visible light. The results demonstrated that UV–visible light accelerated the rate of the reaction, leading to an excellent yield of corresponding products. The recovered palladium nanoparticles could be thermally recycled several times. PdCl2 gave excellent conversion up to the fifth addition of substrate.

Carbon−Carbon Bond Formation and Pyrrole Synthesis via the [3,3] Sigmatropic Rearrangement ofO-Vinyl Oxime Ethers

2010 ◽  
Vol 12 (10) ◽  
pp. 2290-2293 ◽  
Author(s):  
Heng-Yen Wang ◽  
Daniel S. Mueller ◽  
Rachna M. Sachwani ◽  
Hannah N. Londino ◽  
Laura L. Anderson
Keyword(s):  
Bond Formation ◽  
Sigmatropic Rearrangement ◽  
Carbon Bond ◽  
Carbon Carbon Bond

ChemInform Abstract: Highly Enantioselective Carbon-Carbon Bond Formation by Cu-Catalyzed Asymmetric [2,3]-Sigmatropic Rearrangement: Application to the Syntheses of Seven-Membered Oxacycles and Six-Membered Carbocycles.

ChemInform ◽  
2009 ◽  
Vol 40 (13) ◽  
Author(s):  
Gullapalli Kumaraswamy ◽  
Kadivendi Sadaiah ◽  
Duggirala Subrahmanya Ramakrishna ◽  
Naresh Police ◽  
Balasubramanian Sridhar ◽  
...  
Keyword(s):  
Bond Formation ◽  
Sigmatropic Rearrangement ◽  
Carbon Bond ◽  
Carbon Carbon Bond

Highly enantioselective carbon–carbon bond formation by Cu-catalyzed asymmetric [2,3]-sigmatropic rearrangement: application to the syntheses of seven-membered oxacycles and six-membered carbocycles

2008 ◽  
pp. 5324 ◽  
Author(s):  
Gullapalli Kumaraswamy ◽  
Kadivendi Sadaiah ◽  
Duggirala Subrahmanya Ramakrishna ◽  
Naresh Police ◽  
Balasubramanian Sridhar ◽  
...  
Keyword(s):  
Bond Formation ◽  
Sigmatropic Rearrangement ◽  
Carbon Bond ◽  
Carbon Carbon Bond

ChemInform Abstract: Carbon-Carbon Bond Formation and Pyrrole Synthesis via the [3,3] Sigmatropic Rearrangement of O-Vinyl Oxime Ethers.

ChemInform ◽  
2010 ◽  
Vol 41 (40) ◽  
pp. no-no
Author(s):  
Heng-Yen Wang ◽  
Daniel S. Mueller ◽  
Rachna M. Sachwani ◽  
Hannah N. Londino ◽  
Laura L. Anderson
Keyword(s):  
Bond Formation ◽  
Sigmatropic Rearrangement ◽  
Carbon Bond ◽  
Carbon Carbon Bond

Carbon Dioxide-Mediated C(sp2)–H Arylation of Primary and Secondary Benzylamines

2018 ◽  
Author(s):  
Mohit Kapoor ◽  
Pratibha Chand-Thakuri ◽  
Michael Young
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal ◽  
Bond Activation ◽  
Bond Formation ◽  
Carbon Bond ◽  
Chelate Effect ◽  
Free Amine ◽  
Carbon Carbon Bond ◽  
New Strategy ◽  
Metal Catalyzed

Carbon-carbon bond formation by transition metal-catalyzed C–H activation has become an important strategy to fabricate new bonds in a rapid fashion. Despite the pharmacological importance of <i>ortho</i>-arylbenzylamines, however, effective <i>ortho</i>-C–C bond formation from C–H bond activation of free primary and secondary benzylamines using Pd<sup>II</sup> remains an outstanding challenge. Presented herein is a new strategy for constructing <i>ortho</i>-arylated primary and secondary benzylamines mediated by carbon dioxide (CO<sub>2</sub>). The use of CO<sub>2</sub> is critical to allowing this transformation to proceed under milder conditions than previously reported, and that are necessary to furnish free amine products that can be directly used or elaborated without the need for deprotection. In cases where diarylation is possible, a chelate effect is demonstrated to facilitate selective monoarylation.

Modern Organic Synthesis in the Laboratory

2008 ◽  
Author(s):  
Jie Jack Li ◽  
Chris Limberakis ◽  
Derek A. Pflum
Keyword(s):  
Organic Chemistry ◽  
Graduate Students ◽  
Organic Synthesis ◽  
Functional Group ◽  
Bond Formation ◽  
Reaction Conditions ◽  
Carbon Bond ◽  
Oxidation Reduction ◽  
Carbon Carbon Bond ◽  
Daunting Task

Searching for reaction in organic synthesis has been made much easier in the current age of computer databases. However, the dilemma now is which procedure one selects among the ocean of choices. Especially for novices in the laboratory, it becomes a daunting task to decide what reaction conditions to experiment with first in order to have the best chance of success. This collection intends to serve as an "older and wiser lab-mate" one could have by compiling many of the most commonly used experimental procedures in organic synthesis. With chapters that cover such topics as functional group manipulations, oxidation, reduction, and carbon-carbon bond formation, Modern Organic Synthesis in the Laboratory will be useful for both graduate students and professors in organic chemistry and medicinal chemists in the pharmaceutical and agrochemical industries.

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