398-23-2Relevant articles and documents
CpRhIII-Catalyzed Allyl-Aryl Coupling of Olefins and Arylboron Reagents Enabled by C(sp3)-H Activation
Knecht, Tobias,Pinkert, Tobias,Dalton, Toryn,Lerchen, Andreas,Glorius, Frank
, p. 1253 - 1257 (2019)
Herein, we present a mild CpRhIII-catalyzed Suzuki-Miyaura-type allyl-aryl coupling of readily accessible arylboron reagents with a broad range of olefins. Allylic arylation was achieved without the need for prefunctionalized alkenes, and the general Heck-type reactivity between olefins and arenes was not observed. Mechanistic studies indicate that the reaction was enabled through the fast generation of a RhIII-allyl species via undirected C(sp3)-H activation. Moreover, the developed protocol was applied to the highly concise synthesis of the anti-inflammatory drug flurbiprofen.
Water as Solvent for Nickel-2,2′-Bipyridine-Catalysed Electrosynthesis of Biaryls from Haloaryls
Raynal, Frederic,Barhdadi, Rachid,Perichon, Jacques,Savall, Andre,Troupel, Michel
, p. 45 - 49 (2002)
Reductive homocoupling of aryl halides into biaryls was achieved by electrolysis of aqueous emulsions, either in an undivided cell fitted with a sacrificial anode, or in a divided diaphragm cell, and in the presence of nickel-2,2′-bipyridine as catalyst. Reactions were also run in a filter-press cell.
Reactivity studies of cationic Au(III) difluorides supported by N ligands
Sharp-Bucknall, Lachlan,Barwise, Lachlan,Bennetts, Jason D.,Albayer, Mohammad,Dutton, Jason L.
, p. 3344 - 3351 (2020)
The reactivity of difluoro Au(III) cations supported by pyridine or imidazole ligands is reported. The Au(III)?F bond is found to be susceptible to metathesis by TMS reagents and reagents bearing acidic protons such as H?CC?Ph and HOAc. In the last case the reactions are slower than analogous reactions reported by other groups, where strong trans donors are present opposite the Au?F bond. This, coupled with the inability to effect metathesis on only one Au?F bond in our system, indicates that the trans effect is a key consideration in Au?F chemistry.
Shaw,Turner
, p. 509,511 (1932)
Pre-transmetalation intermediates in the Suzuki-Miyaura reaction revealed: The missing link
Thomas, Andy A.,Denmark, Scott E.
, p. 329 - 332 (2016)
Despite the widespread application of Suzuki-Miyaura cross-coupling to forge carbon-carbon bonds, the structure of the reactive intermediates underlying the key transmetalation step from the boron reagent to the palladium catalyst remains uncertain. Here we report the use of low-temperature rapid injection nuclear magnetic resonance spectroscopy and kinetic studies to generate, observe, and characterize these previously elusive complexes. Specifically, this work establishes the identity of three different species containing palladium-oxygen-boron linkages, a tricoordinate boronic acid complex, and two tetracoordinate boronate complexes with 2:1 and 1:1 stoichiometry with respect to palladium. All of these species transfer their boron-bearing aryl groups to a coordinatively unsaturated palladium center in the critical transmetalation event.
Competitive gold/nickel transmetalation
Austen, Brady J. H.,Demchuk, Mitchell J.,Drover, Marcus W.,Nelson, David J.,Zurakowski, Joseph A.
supporting information, p. 68 - 71 (2021/12/29)
Transmetalation is a key method for the construction of element-element bonds. Here, we disclose the reactivity of [NiII(Ar)(I)(diphosphine)] compounds with arylgold(i) transmetalating agents, which is directly relevant to cross-coupling catalysis. Both aryl-for-iodide and unexpected aryl-for-aryl transmetalation are witnessed. Despite the strong driving force expected for Au-I bond formation, aryl scrambling can occur during transmetalation and may complicate the outcomes of attempted catalytic cross-coupling reactions.
Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
, (2021/01/11)
Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.
