- Copper-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides
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An unprecedented CuI-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides is reported. Mechanistic studies with a Cp2ZrAr2 complex revealed that Cp2Zr(Ar)(Cl) is the reactive species that undergoes transmetalation with (PN-1)CuI. In addition, experiments with radical probes indicated that the reaction proceeds via a non-radical pathway. This journal is
- Thapa, Surendra,Basnet, Prakash,Gurung, Santosh K.,Giri, Ramesh
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supporting information
p. 4009 - 4012
(2015/03/30)
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- Borylation using group IV metallocene under mild conditions
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A borylation reaction of aromatic diazonium salts has been optimized using titanocene and zirconocene derivatives as catalysts. The reaction employs diisopropylaminoborane as a borylating agent and proceeds smoothly at room temperature to provide arylboronates after methanolysis and transesterification with pinacol. The reaction mechanism has been found to proceed via a radical pathway.
- Marciasini, Ludovic D.,Vaultier, Michel,Pucheault, Mathieu
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p. 1702 - 1705
(2014/03/21)
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- Cationic zirconocene and hafnocene aryl complexes
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Cationic (C5H4R)2ZrAr+ aryl species (2a-d: R = H; Ar = o-tolyl (a), 2-Me-4-F-C6H3 (b), 3-F-C6H4 (c), Ph (d); 2e: R = Me, Ar = Ph) are generated by the reaction of a 1:1 mixture of (C5H4R) 2ZrAr2 and (C5H4R) 2ZrMe2 with 2 equiv of [CPh3][B(C 6F5)4] via methide abstraction and ligand exchange steps. Complex 2d and the Cp2HfAr+ analogues (2f,g: Ar = o-tolyl (f), Ph (g)) are generated by the reaction Of Cp 2MAr2 with [C6Me6H] [B (C 6F5)4]. NMR studies suggest that these metallocene aryl cations exist as (C5H4R) 2M(Ar)(RCl)+ solvent adducts in chlorocarbon solution. NMR and DFT studies show that the (C5H4R)2Zr(Ar) (RCl)+ species contain β-C-H-Zr agostic interactions involving an ortho-aryl hydrogen. The endo isomers, in which the β-agostic interaction occupies the central coordination site, are ca. 5 kcal/mol more stable than the exo isomers, in which the β-agostic interaction occupies a lateral site. The aryl agostic interactions are weaker for Hf than Zr, and Cp2Hf(Ph)(C 6D5Cl)+ (2g·C6D 5Cl) does not contain an agostic interaction.
- Sydora, Orson L.,Kilyanek, Stefan M.,Jordan, Richard F.
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p. 4746 - 4755
(2008/10/09)
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