Heck-type coupling vs. conjugate addition in phosphine–rhodium catalyzed reactions of aryl boronic acids with α,β-unsaturated carbonyl compounds: a systematic investigation

2007 ◽  
pp. 3055-3064 ◽  
Author(s):  
Gang Zou ◽  
Jianping Guo ◽  
Zhiyong Wang ◽  
Wen Huang ◽  
Jie Tang
Keyword(s):  
Carbonyl Compounds ◽  
Conjugate Addition ◽  
Systematic Investigation ◽  
Boronic Acids ◽  
Type Coupling ◽  
Catalyzed Reactions

Synthetic Scope of Brønsted Acid-Catalyzed Reactions of Carbonyl Compounds and Ethyl Diazoacetate

2021 ◽  
Author(s):  
Mizzanoor Rahaman ◽  
M. Shahnawaz Ali ◽  
Khorshada Jahan ◽  
Damon Hinz ◽  
Jawad Bin Belayet ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Ethyl Diazoacetate ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

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.

Conjugate addition of dimethylphenylsilyllithium to α,β-unsaturated carbonyl compounds mediated by sub-stoichiometric quantities of dimethylzinc

1997 ◽  
Vol 38 (42) ◽  
pp. 7313-7316 ◽  
Author(s):  
Bonnie L. MacLean ◽  
Kimberlea A. Hennigar ◽  
Kevin W. Kells ◽  
Robert D. Singer
Keyword(s):  
Carbonyl Compounds ◽  
Conjugate Addition
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