Regioselectivity in C–H activation: reagent control in cyclometallation of 2-(1-naphthyl)-pyridine. Issue 2 (24th November 2015)

• Record Type: Journal Article
• Authors: Kondrashov, Mikhail; Provost, David; Wendt, Ola F.
• Is Part Of: Dalton transactions. Volume 45:Issue 2(2016)
• Page Start: 525
• Page End: 531
• Publication Date: 2015-11-24
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c5dt04068j
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The choice of metallating agent completely reverses the regioselectivity in cyclometallation of 2-(1-naphthyl)-pyridine. Abstract : 2-(1-Naphthyl)-pyridine (1 ) possesses sp 2 C–H bonds in both the γ- and δ-positions and is therefore a suitable substrate for studying the cyclometallation selectivity with different reagents and conditions. Such selectivity studies are reported. Based on deuterium-exchange experiments it is concluded that cycloruthenation with RuCl2 ( p -cymene) dimer is reversible with kinetic and thermodynamic preference for γ-substitution. Electrophilic cycloborylation, on the other hand, shows unusual δ-substitution. The previously published cyclopalladation and cycloauration of the substrate was studied in detail and was shown to be irreversible; they proceed under kinetic control and give γ- and δ-substitution for palladium and gold, respectively.