Direct introduction of a naphthalene-1,8-diamino boryl [B(dan)] group by a Pd-catalysed selective boryl transfer reaction

2015 ◽  
Vol 51 (26) ◽  
pp. 5656-5659 ◽  
Author(s):  
Liang Xu ◽  
Pengfei Li
Keyword(s):  
Transfer Reaction ◽  
Boronic Acids ◽  
Reaction Conditions ◽  
Direct Introduction ◽  
Type Reaction ◽  
Aryl Bromides

Under Palladium-catalysed Miyaura-type reaction conditions, a non-symmetrical diboron reagent, B(pin)-B(dan), was found to selectively deliver the B(dan) moiety to aryl bromides and chlorides. This method represents a direct and efficient way to masked boronic acids and boron-differentiated di- and polyboron compounds.

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.

Preparation of aromatic amines by copper-catalyzed coupling of boronic acids with aqueous ammonia

2010 ◽  
Vol 88 (9) ◽  
pp. 964-968 ◽  
Author(s):  
Zhaoqiong Jiang ◽  
Zhiqing Wu ◽  
Lixia Wang ◽  
Di Wu ◽  
Xiangge Zhou
Keyword(s):  
Aromatic Amines ◽  
Aqueous Ammonia ◽  
Environmentally Friendly ◽  
Boronic Acids ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Primary Aromatic Amines

A simple, highly efficient, and environmentally friendly protocol for the synthesis of primary aromatic amines by catalytic coupling of aromatic boronic acids with aqueous ammonia has been developed by using commercial and inexpensive CuSO4·5H2O as catalyst without addition of other solvents under mild reaction conditions.

scholarly journals Selective C-N σ Bond Cleavage in Azetidinyl Amides under Transition Metal-Free Conditions

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 459 ◽  
Author(s):  
Hengzhao Li ◽  
Zemin Lai ◽  
Adila Adijiang ◽  
Hongye Zhao ◽  
Jie An
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Transfer Reaction ◽  
Bond Cleavage ◽  
Electron Transfer Reaction ◽  
Amide Bond ◽  
Single Electron Transfer ◽  
Reaction Conditions ◽  
Metal Free ◽  
Single Electron Transfer Reaction

Functionalization of amide bond via the cleavage of a non-carbonyl, C-N σ bond remains under-investigated. In this work, a transition-metal-free single-electron transfer reaction has been developed for the C-N σ bond cleavage of N-acylazetidines using the electride derived from sodium dispersions and 15-crown-5. Of note, less strained cyclic amides and acyclic amides are stable under the reaction conditions, which features the excellent chemoselectivity of the reaction. This method is amenable to a range of unhindered and sterically encumbered azetidinyl amides.

An Example of Ketone Olefination via Praseodymium-Mediated Barbier Reaction in the Presence of Diethyl Phosphite

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1437-1441
Author(s):  
Xu yan Cao ◽  
Fei Huang ◽  
Songlin Zhang
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Point Of View ◽  
Diethyl Phosphite ◽  
Reaction Conditions ◽  
One Pot ◽  
Type Reaction ◽  
Mild Conditions ◽  
Allyl Halides ◽  
Barbier Reaction

The first example of carbon double-bond formation via praseodymium-mediated Barbier type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported. The reaction is highly α-regioselective and conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with practical reaction conditions.

scholarly journals Carbonylative Suzuki–Miyaura couplings of sterically hindered aryl halides: synthesis of 2-aroylbenzoate derivatives

2020 ◽  
Vol 18 (9) ◽  
pp. 1754-1759 ◽  
Author(s):  
Aya Ismael ◽  
Troels Skrydstrup ◽  
Annette Bayer
Keyword(s):  
Boronic Acid ◽  
Boronic Acids ◽  
Aryl Halides ◽  
Aryl Bromides ◽  
Sterically Hindered

A new protocol for carbonylative coupling of sterically hindered aryl bromides with boronic acids featuring slow addition of the boronic acid as a strategy to suppress unwanted non-carbonylative couplings for sterically hindered aryl bromides.

Synthesis, characterization, and reactivity of Pd(II) salicylaldimine complexes derived from aminophenols

2007 ◽  
Vol 85 (5) ◽  
pp. 392-399 ◽  
Author(s):  
Bennett J Tardiff ◽  
Joshua C Smith ◽  
Stephen J Duffy ◽  
Christopher M Vogels ◽  
Andreas Decken ◽  
...  
Keyword(s):  
Schiff Base ◽  
Green Chemistry ◽  
Schiff Bases ◽  
Cross Coupling ◽  
Boronic Acids ◽  
Aryl Bromides

Schiff bases, derived from the condensation of salicylaldehydes with 3- and 4-aminophenol, reacted with palladium(II) acetate to give the corresponding bis(N-arylsalicylaldiminato)palladium(II) complexes. These complexes have been found to be active catalysts for the Suzuki–Miyaura cross-coupling of aryl bromides and iodides with aryl boronic acids, using water as a solvent.Key words: cross-coupling, green chemistry, palladium, salicylaldimines, Schiff base, Suzuki–Miyaura.

A chiral Brønsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines

2018 ◽  
Vol 54 (28) ◽  
pp. 3516-3519 ◽  
Author(s):  
Rajshekhar A. Unhale ◽  
Milon M. Sadhu ◽  
Sumit K. Ray ◽  
Rayhan G. Biswas ◽  
Vinod K. Singh
Keyword(s):  
Phosphoric Acid ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Chiral Phosphoric Acid ◽  
Brönsted Acid ◽  
Diazo Esters ◽  
Reaction Proceeds ◽  
Acid Catalyzed ◽  
Chiral Bronsted Acid

A chiral phosphoric acid-catalyzed asymmetric Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-aryl-3-hydroxyisoindolinones has been demonstrated. The reaction proceeds smoothly under mild reaction conditions.

scholarly journals Palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides

2017 ◽  
Vol 13 ◽  
pp. 2610-2616 ◽  
Author(s):  
Tao Fan ◽  
Wei-Dong Meng ◽  
Xingang Zhang
Keyword(s):  
Alkyl Radical ◽  
Functional Group ◽  
High Efficiency ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Alkyl Bromides ◽  
Reaction Proceeds ◽  
Palladium Catalyzed ◽  
Hydroxy Groups

An efficient palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides has been developed. The reaction proceeds under mild reaction conditions with high efficiency and excellent functional group tolerance, even towards formyl and hydroxy groups. Preliminary mechanistic studies reveal that a secondary trifluoromethylated alkyl radical is involved in the reaction.

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