1,4‐Conjugate Addition of Aryl boronic Acids on Cyclohexenone as Catalyzed by Rhodium(I) Complexes of C 2 ‐Symmetric Bioxazoline Fused N‐heterocyclic Carbenes

2019 ◽  
Vol 4 (29) ◽  
pp. 8526-8533 ◽  
Author(s):  
Balasubramaniyam Ramasamy ◽  
A. P. Prakasham ◽  
Manoj Kumar Gangwar ◽  
Prasenjit Ghosh
Keyword(s):  
Conjugate Addition ◽  
Boronic Acids ◽  
Heterocyclic Carbenes

scholarly journals Rate Dependence on Inductive and Resonance Effects for the Organocatalyzed Enantioselective Conjugate Addition of Alkenyl and Alkynyl Boronic Acids to β-Indolyl Enones and β-Pyrrolyl Enones

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1615
Author(s):  
Amy Boylan ◽  
Thien S. Nguyen ◽  
Brian J. Lundy ◽  
Jian-Yuan Li ◽  
Ravikrishna Vallakati ◽  
...  
Keyword(s):  
Positive Charge ◽  
Bond Formation ◽  
Conjugate Addition ◽  
Reaction Rates ◽  
Boronic Acids ◽  
Key Factors ◽  
Resonance Contribution ◽  
Reaction Conditions ◽  
Resonance Effects ◽  
Resonance Stabilization

Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.

scholarly journals Rh-Catalyzed Conjugate Addition of Aryl and Alkenyl Boronic Acids to α-Methylene-β-lactones: Stereoselective Synthesis of trans-3,4-Disubstituted β-Lactones

2017 ◽  
Vol 19 (17) ◽  
pp. 4460-4463 ◽  
Author(s):  
Christian A. Malapit ◽  
Irungu K. Luvaga ◽  
Donald R. Caldwell ◽  
Nicholas K. Schipper ◽  
Amy R. Howell
Keyword(s):  
Stereoselective Synthesis ◽  
Conjugate Addition ◽  
Boronic Acids

PdII-Catalyzed Conjugate Addition of Boronic Acids to Ketoglutaconic Esters toward the Synthesis of Functionalized Pyridazin-3(2H)-ones with Neuroprotective Activity

2012 ◽  
Vol 2012 (27) ◽  
pp. 5398-5405 ◽  
Author(s):  
Silvia Roscales ◽  
Andrea Ortega ◽  
Sagrario Martín-Aragón ◽  
Paloma Bermejo-Bescós ◽  
Aurelio G. Csákÿ
Keyword(s):  
Conjugate Addition ◽  
Boronic Acids ◽  
Neuroprotective Activity

Asymmetric Synthesis with N-Heterocyclic Carbenes. Application to the Copper-Catalyzed Conjugate Addition.

ChemInform ◽  
2003 ◽  
Vol 34 (28) ◽  
Author(s):  
Alexandre Alexakis ◽  
Caroline L. Winn ◽  
Frederic Guillen ◽  
Julien Pytkowicz ◽  
Sylvain Roland ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Conjugate Addition ◽  
Heterocyclic Carbenes

Strategy of total synthesis based on the use of Rh-catalyzed stereoselective 1,4-addition

2015 ◽  
Vol 13 (35) ◽  
pp. 9168-9175 ◽  
Author(s):  
M. Jean ◽  
B. Casanova ◽  
S. Gnoatto ◽  
P. van de Weghe
Keyword(s):  
Total Synthesis ◽  
Conjugate Addition ◽  
Boronic Acids ◽  
Rhodium Complexes ◽  
Unsaturated Ketones

In 1998, Hayashi and Miyaura reported the first asymmetric conjugate addition of aryl- and alkenyl-boronic acids to α,β-unsaturated ketones using chiral rhodium complexes as catalysts.

Enantioselective copper catalysed 1,4-conjugate addition reactions using chiral N-heterocyclic carbenes

2005 ◽  
Vol 690 (24-25) ◽  
pp. 5672-5695 ◽  
Author(s):  
Caroline L. Winn ◽  
Frédéric Guillen ◽  
Julien Pytkowicz ◽  
Sylvain Roland ◽  
Pierre Mangeney ◽  
...  
Keyword(s):  
Conjugate Addition ◽  
Heterocyclic Carbenes ◽  
Addition Reactions

Water enhanced synthesis of gem-bisphosphonates via Rh(i) mediated 1,4-conjugate addition of aryl boronic acids to vinylidenebisphosphonate esters

2013 ◽  
Vol 15 (3) ◽  
pp. 656 ◽  
Author(s):  
Giulio Bianchini ◽  
Alessandro Scarso ◽  
Andrea Chiminazzo ◽  
Laura Sperni ◽  
Giorgio Strukul
Keyword(s):  
Conjugate Addition ◽  
Boronic Acids
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