The Stereochemistry of Conjugate Additions. Convergent Configuration Control in Additions of Morpholine and N-Bromomorpholine to cis- and trans-α,β-Unsaturated Ketones

1959 ◽  
Vol 81 (20) ◽  
pp. 5435-5441 ◽  
Author(s):  
Philip L. Southwick ◽  
Raymond J. Shozda
Keyword(s):  
Conjugate Additions ◽  
Unsaturated Ketones ◽  
Cis And Trans ◽  
Configuration Control

ChemInform Abstract: THE ROLE OF SOLVENT IN CONJUGATE ADDITIONS LEADING TO CIS- AND TRANS-1-ALKYL-2-ARYL-3-CARBO(AROYL)AZIRIDINES

1977 ◽  
Vol 8 (40) ◽  
pp. no-no
Author(s):  
P. TARBURTON ◽  
P. B. WOLLER ◽  
R. C. BADGER ◽  
E. DOOMES ◽  
N. H. CROMWELL
Keyword(s):  
Conjugate Additions ◽  
Cis And Trans ◽  
Role Of Solvent

Asymmetric conjugate additions of 2-substituted benzofuran-3(2H)-ones to α,β-unsaturated ketones catalyzed by chiral copper complexes

2017 ◽  
Vol 15 (19) ◽  
pp. 4191-4198 ◽  
Author(s):  
Haojiang Wang ◽  
Yifeng Wang ◽  
Cheng Zhang ◽  
Yidong Jiang ◽  
Mingming Chu ◽  
...  
Keyword(s):  
Copper Complexes ◽  
Conjugate Addition ◽  
Conjugate Additions ◽  
Unsaturated Ketones

A highly enantioselective conjugate addition of 2-substituted benzofuran-3(2H)-ones to α,β-unsaturated ketones promoted by chiral copper complexes has been developed.

scholarly journals The facile dearomatization of nitroaromatic compounds using lithium enolates of unsaturated ketones in conjugate additions and (4+2) formal cycloadditions

2019 ◽  
Vol 55 (52) ◽  
pp. 7494-7497 ◽  
Author(s):  
Karine Pasturaud ◽  
Batoul Rkein ◽  
Morgane Sanselme ◽  
Muriel Sebban ◽  
Sami Lakhdar ◽  
...  
Keyword(s):  
Nitroaromatic Compounds ◽  
The Novel ◽  
Conjugate Additions ◽  
Unsaturated Ketones ◽  
Lithium Enolates

The novel nucleophilic activation of enolizable unsaturated ketones allows their addition to nitroaromatics and furnishes the corresponding formal dearomatized (4+2) cycloadducts.

Conjugate Additions of Cyclic Oxygen-Bound Nickel Enolates to α,β-Unsaturated Ketones

2007 ◽  
Vol 13 (13) ◽  
pp. 3675-3687 ◽  
Author(s):  
Celia M. Maya ◽  
Juan Cámpora ◽  
Ernesto Carmona ◽  
Inmaculada Matas ◽  
Pilar Palma ◽  
...  
Keyword(s):  
Conjugate Additions ◽  
Unsaturated Ketones

scholarly journals Retooling Asymmetric Conjugate Additions for Sterically Demanding Substrates with an Iterative Data-Driven Approach

2019 ◽  
Author(s):  
Alexandre Brethomé ◽  
Robert Paton ◽  
Stephen P. Fletcher
Keyword(s):  
Functional Groups ◽  
Conjugate Addition ◽  
Data Driven ◽  
Quantitative Structure ◽  
Conjugate Additions ◽  
Unsaturated Ketones ◽  
Alkyl Chains ◽  
Reaction Optimization ◽  
Sterically Demanding ◽  
Data Driven Approach

The development of new catalytic enantioselective methods is routinely carried out using easily accessible and prototypical substrates. This approach to reaction development often yields asymmetric methods that perform poorly using substrates sterically or electronically dissimilar to those used during the reaction optimization campaign. Consequently, expanding the scope of previously optimized catalytic asymmetric reactions to include new substrates is decidedly non-trivial. Here we address this challenge through the development of a systematic workflow to broaden the applicability and reliability of asymmetric conjugate additions to substrates conventionally regarded as sterically and electronically challenging. The copper-catalyzed asymmetric conjugate addition of alkylzirconium nucleophiles to form tertiary centers, although successful for linear alkyl chains, fails for more sterically demanding linear α,β-unsaturated ketones. Key to adapting this method to obtain high enantioselectivity was the discovery of new phosphoramidite ligands, designed using quantitative structure-selectivity relationships (QSSR). Iterative rounds of model construction and ligand synthesis were executed in parallel to evaluate the performance of twenty chiral ligands. The copper-catalyzed asymmetric addition is now more broadly applicable, even tolerating linear enones bearing tert-butyl β-substituents. The presence of common functional groups is tolerated in both nucleophiles and electrophiles, giving up to 99% yield and 95% ee across twenty examples.

13C magnetic resonance studies. 144. An examination of β-enolization in the bicyclo[3.3.1]- and [3.2.2]nonan-2-one system

1993 ◽  
Vol 71 (8) ◽  
pp. 1099-1105 ◽  
Author(s):  
David J. Muir ◽  
J.B. Stothers
Keyword(s):  
Electron Transfer ◽  
Magnetic Resonance ◽  
Major Product ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Magnetic Resonance Studies ◽  
Unsaturated Ketones ◽  
A Minor ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra

While 3,3-dimethylbicyclo[3.3.1]nonan-2-one (5) is stable under strongly basic conditions (t-BuO−/t-BuOH/185 °C), its isomer, 3,3-dimethylbicyclo[3.2.2]nonan-2-one (6), is slowly transformed to 5. Similarly, 3,3-dimethylbicyclo-[3.2.2]non-6-en-2-one (8b) rearranges to a [3.3.1] isomer but the latter is not stable. Experiments with 3,3-dimethylbicyclo[3.3.1]non-6-en-2-one (7) revealed that it is converted to five compounds, none of which is 8b. The major product, 8,8-dimethylbicyclo[4.3.0]non-1(6),-en-7-one (11) arises from β-enolate rearrangement. Enone 11 undergoes slow reduction to cis- and trans-8,8-dimethylbicyclo[4.3.0]nonan-7-one, presumably by single electron transfer. Experiments with 11 alone showed that β-enolate rearrangement of 7 → 11 is unidirectional. Haller–Bauer cleavage to acidic products occurs as a minor process in the reactions of the unsaturated ketones. The structures of the products were established primarily from their 1H and 13C magnetic resonance spectra.

Highly Enantioselective Conjugate Additions to α,β-Unsaturated Ketones Catalyzed by a (Salen)Al Complex

2005 ◽  
Vol 127 (4) ◽  
pp. 1313-1317 ◽  
Author(s):  
Mark S. Taylor ◽  
David N. Zalatan ◽  
Andreas M. Lerchner ◽  
Eric N. Jacobsen
Keyword(s):  
Conjugate Additions ◽  
Unsaturated Ketones
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