Double bond isomerizations in unsaturated esters and enol ethers. I. Equilibrium studies in cyclic and acyclic systems

1970 ◽  
Vol 35 (10) ◽  
pp. 3352-3358 ◽  
Author(s):  
Sara J. Rhoads ◽  
Jitendra K. Chattopadhyay ◽  
Edward E. Waali
Keyword(s):  
Double Bond ◽  
Equilibrium Studies ◽  
Enol Ethers ◽  
Unsaturated Esters

?syn-Effect? in the Conversion of (E)-?,?-Unsaturated Esters into the Corresponding ?,?-Unsaturated Esters and Aldehydes into Silyl Enol Ethers.

ChemInform ◽  
2005 ◽  
Vol 36 (15) ◽  
Author(s):  
Samar Kumar Guha ◽  
Atsushi Shibayama ◽  
Daisuke Abe ◽  
Maki Sakaguchi ◽  
Yutaka Ukaji ◽  
...  
Keyword(s):  
Enol Ethers ◽  
Unsaturated Esters ◽  
Silyl Enol Ethers

Reduction of conjugate double bonds with trichlorosilane

2000 ◽  
Vol 78 (11) ◽  
pp. 1396-1398 ◽  
Author(s):  
Moni Chauhan ◽  
Philip Boudjouk
Keyword(s):  
Double Bond ◽  
Carbonyl Compounds ◽  
Double Bonds ◽  
Cyclic Ketones ◽  
Unsaturated Esters ◽  
Mild Conditions ◽  
Carbon Double Bond

A variety of α,β-unsaturated esters and cyclic ketones underwent smooth reduction of the carbon–carbon double bond with a combination of inexpensive and readily available trichlorosilane and CoCl2. The reactions are performed under very mild conditions and products are obtained in high yields.Key words: reduction, carbonyl compounds, trichlorosilane, ketones, chemoselectivity.

scholarly journals Design of Boradecarboxylation Reaction

2020 ◽  
Author(s):  
Yuji Naruse ◽  
Atsushi Takamori ◽  
Kenji Oda
Keyword(s):  
Double Bond ◽  
Theoretical Calculation ◽  
Polar Solvent ◽  
Theoretical Calculations ◽  
Lone Pair ◽  
Carbonyl Groups ◽  
Orbital Theory ◽  
Enol Ethers ◽  
Decarboxylation Reaction ◽  
Boat Form

For mechanism of decarboxylation reaction, all textbooks show that the electron moves from the pi<sub>C=O</sub> bond. However, the most donating bond orbital in the carbonyl group should be the lone pair(s) on the oxygen. Thus, a picture of orbital theory with delocalization from a lone pair should be more appropriate than that from the pi<sub>C=O</sub> orbital. We confirmed our idea by theoretical calculation. In the TS, if we use 2-substituted b-ketoacids, the boat-form conformation should result in exclusively preferred generation of <i>E</i>-enolates. Normally, decarboxylation reaction performs in polar solvent, so that the resulting enols should be transformed to the corresponding ketones by tautomerization. Suppose we use the heteroatoms to obtain the enolate or enol ethers without tautomerization, it would offer a diastereoselective enol(ate) synthesis with regioselectivity, since the C=C double bond should always be introduced between two carbonyl groups. After screening the heteroatoms by the theoretical calculations, we found that boron is suitable for this purpose. We confirmed our idea by theoretical calculations, offering a new boradecarboxylation reaction to produce enolates diastereoselecitively and regioselectively.

Asymmetric Synthesis of Ethers by Catalytic Alkene Hydro­alkoxy­lation

Synthesis ◽  
2020 ◽  
Vol 52 (15) ◽  
pp. 2127-2146
Author(s):  
Zhi Li ◽  
Wen-Bin Xie
Keyword(s):  
Asymmetric Synthesis ◽  
Carboxylic Acids ◽  
Carbonyl Compounds ◽  
High Reactivity ◽  
Enol Ethers ◽  
Unsaturated Esters ◽  
Unsaturated Ketones ◽  
Recent Developments ◽  
Catalytic Asymmetric

Many chiral ethers have important physiological activities. Although many asymmetric hydroalkoxylations of olefins with alcohols or phenols have been developed to make chiral ethers, challenges still remain in achieving high reactivity and selectivity over an ever-increasing diversity of alkenes and alcohols. In this review, recent developments on catalytic asymmetric alkene hydroalkoxylations are summarized based on the substitution patterns of alkenes.1 Introduction2 Asymmetric Hydroalkoxylation of Non-Activated Alkenes2.1 Intramolecular Additions2.2 Intermolecular Additions3 Asymmetric Hydroalkoxylation of Enol Ethers3.1 Intramolecular Additions3.2 Intermolecular Additions4 Asymmetric Hydroalkoxylation of α,β-Unsaturated Carbonyl Compounds4.1 α,β-Unsaturated Ketones and Aldehydes as Substrates4.2 α,β-Unsaturated Esters, Amides and Carboxylic Acids as Substrates5 Asymmetric Hydroalkoxylation of Allenes5.1 Intramolecular Additions5.2 Intermolecular Additions6 Conclusion

Accessing 1,2-Amino Alcohols and Diols through Photocatalytic Anti-Markovnikov Difunctionalisation of Ene-Carbamates and Enol Ethers

2020 ◽  
Author(s):  
Jerome Waser ◽  
Stefano Nicolai ◽  
Stephanie G. E. Amos
Keyword(s):  
Double Bond ◽  
Radical Cation ◽  
Amino Alcohol ◽  
Oxygen Transfer ◽  
Room Temperature ◽  
Organic Dye ◽  
Enol Ethers ◽  
Blue Led ◽  
Broad Variety ◽  
Led Irradiation

We report an atom-economical 1,2-oxyalkynylation of ene-carbamates and enol ethers based on the use of Ethynyl BenziodoXolone (EBX) as dual reagents for alkyne and oxygen transfer. The reaction occurs at room temperature under blue LED irradiation using an organic dye as a photocatalyst. A broad variety of 1-alkynyl-1,2-amino-alcohol and 1-alkynyl-1,2-diol scaffolds were obtained in up to 89% yield with anti-Markovnikov regioselectivity. The reaction is speculated to proceed via oxidation of the double bond to give a radical cation intermediate, enabling the selective difunctionalization of electron-rich alkenes.

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