Palladium−Imidazolium Carbene Catalyzed Aryl, Vinyl, and Alkyl Suzuki−Miyaura Cross Coupling

Abstract

[reaction--see text] N,N-Bis-(2,6-diisopropylphenyl)dihydroimidazolium chloride with palladium(II) acetate (2 mol %) was used as catalyst, without added base, to efficiently cross couple aryl, vinyl, and alkyl boronates and boronic acids with aryldiazonium tetrafluoroborate substrates. The reactions were performed at 0 degrees C or rt, giving product in 2 to 4 h with 80 to 90% yields for isolated materials. Diazonium ions, formed in situ, also cross couple under these conditions.

Palladium Complexes of N‐Heterocyclic Carbenes as Catalysts for Cross‐Coupling Reactions—A Synthetic Chemist's Perspective

“…Vinyl halides and triflates [183] and arenediazonium salts [189] underwent coupling reactions with arylboronic acids in the presence of Pd(OAc) 2 and bulky ligand precursors, the phenanthrene-substituted imidazolium salt 218 (Scheme 56) and SIPr·HCl (13, 3 ] was utilized. [190] Similarly, the sulfonyl chloride group could be activated selectively over a chloro or bromo, but not an iodo substituent.…”

Aus der Sicht des Synthetikers: Palladiumkomplexe N‐heterocyclischer Carbene als Katalysatoren für Kreuzkupplungen

“…[83] Wir verwendeten überdies die sperrigen Adamantylsubstituenten, um aus verschiedenen Kombinationen von elektronenarmen und elektronenreichen Reaktionspartnern para,para'-substituierte Biphenyle zu erhalten (Abbildung 4); [74] auch Benzimidazoliumsalze mit kleineren Substituenten waren erfolgreich. [184] [183] sowie Aryldiazoniumsalze [189] wurden mit Arylboronsäuren gekuppelt, wobei als Katalysator Pd(OAc) 2 [189] und Pinacolborane [191] (Schema 62). Besonders erwähnenswert ist der Einsatz von Cyclohexylpinacolboran, dem bislang einzigen sekundären Alkylnucleophil in einer Kreuzkupplung mit einem NHC-Pd-Katalysator (Produkt 259, Schema 62).…”

Nickel(0)/Imidazolium Carbene Catalyst System for Efficient Cross‐Coupling of Aryl Bromides and Chlorides with Organomanganese Reagents

“…4-Methoxybiphenyl (6a), [22] 4-methoxy-2'-methylbiphenyl (6b), [23] 4-methoxy-3'-methylbiphenyl (6c), [24] 4-methoxy-4'-methylbiphenyl (6d), [25] 2-methoxybiphenyl (6e), [26] 4-dimethylamino-4'-methoxybiphenyl (6f), [27] 4-fluoro-4'-methoxybiphenyl (6h), [28] 2-fluoro-2'-methoxybiphenyl (6i), [29] 4-methoxy-3'-trifluoromethylbiphenyl (6k), [30] 4-methoxy-4'-trifluoromethylbiphenyl (6l), [24] 2-carbomethoxy-4'-methoxybiphenyl (6m), [31] 4-carbomethoxy-4'-methoxybiphenyl (6p), [32] 4-(4'-methoxyphenyl)benzophenone (6r), [33] 2-(4-methoxyphenyl)pyridine (6u)…”