Impact of reducing agent, temperature, and substrate topology on diastereoselectivity of the intermolecular coupling reactions, or how “free” are cobalt-complexed propargyl radicals?

2013 ◽  
Vol 42 (41) ◽  
pp. 14801 ◽  
Author(s):  
Gagik G. Melikyan ◽  
Louis Carlson ◽  
Nare Sahakyan ◽  
Arthur Floruti ◽  
McKinzie Garrison
Keyword(s):  
Reducing Agent ◽  
Coupling Reactions ◽  
Propargyl Radicals ◽  
Intermolecular Coupling

A Study on the Reactivity of Monosubstituted Benzenes in the MW-Assisted Pd(OAc)2-catalyzed Hirao Reaction with Ph2P(O)H and (EtO)2P(O)H Reagents

2020 ◽  
Vol 24 (9) ◽  
pp. 1048-1054 ◽  
Author(s):  
Réka Henyecz ◽  
Bianka Huszár ◽  
Viktória Grenitzer ◽  
György Keglevich
Keyword(s):  
Induction Period ◽  
Coupling Reaction ◽  
Reducing Agent ◽  
Diethyl Phosphite ◽  
Coupling Reactions ◽  
Diphenylphosphine Oxide ◽  
Lower Reactivity ◽  
Monosubstituted Benzenes ◽  
Reactivity Order

The reactivity order of “iodobenzene > bromobenzene > phenyl trifluoromethanesulfonate” was established in microwave (MW)-assisted Pd(OAc)2-catalyzed P–C coupling reactions with diphenylphosphine oxide and diethyl phosphite, where the excess of the these >P(O)H reagents served as the reducing agent, and, via its tautomeric >P-OH form, also as the P-ligand. The P–C coupling of Ph2P(O)H with PhBr at 120 °C took place via an induction period, during which the active “P-Pd-P” catalyst was formed from the Pd(II) salt and the >P(O)H species. The lower reactivity of PhBr towards Ph2P(O)H could be promoted by the addition of 20% of KI to the reaction mixture at 120 °C, or utilizing 1 equivalent of KI after a pre-reaction with PhBr at 120-150 °C followed by the P–C coupling at 100 °C. The reactivity of PhOTf and a bromo analogue was compared in competitive couplings with Ph2P(O)H. Beyond this, the reactivity of Ph2P(O)H and (EtO)2P(O)H towards PhOTf was evaluated in another competitive experiment. Increasing the scale of the P–C coupling reaction of (EtO)2P(O)H with PhBr, the quantity for the components of the catalyst could be decreased.

Samarium(II) Iodide Mediated Intermolecular Coupling Reactions of N,N-Dibenzyl-α-haloamides with Carbonyl Compounds

Synthesis ◽  
1996 ◽  
Vol 1996 (08) ◽  
pp. 970-974 ◽  
Author(s):  
Yutaka Aoyagi ◽  
Rie Asakura ◽  
Nobuko Kondoh ◽  
Rieko Yamamoto ◽  
Takeshi Kuromatsu ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Coupling Reactions ◽  
Intermolecular Coupling

scholarly journals A concise synthesis of 3-(1-alkenyl)isoindolin-1-ones and 5-(1-alkenyl)pyrrol-2-ones by the intermolecular coupling reactions of N-acyliminium ions with unactivated olefins

2012 ◽  
Vol 8 ◽  
pp. 192-200 ◽  
Author(s):  
Nianhong Lu ◽  
Lihong Wang ◽  
Zhanshan Li ◽  
Wei Zhang
Keyword(s):  
Room Temperature ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Acyliminium Ions ◽  
Intermolecular Coupling

A concise synthesis of 3-(1-alkenyl)isoindolin-1-ones and 5-(1-alkenyl)pyrrol-2-ones has been achieved by the coupling reactions of N-acyliminium ions produced from 3-hydroxyisoindol-1-ones or 5-hydroxy-1-pyrrol-2-ones with unactivated olefins in the presence of BF3·OEt2 at room temperature. For most of the olefins, the reactions afforded the Csp3–Csp2 cross-coupling products, but for the α-methylstyrene and 1-hexene, the Csp3–Csp3 cross-coupling products were obtained.

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