title: Selective C-C coupling at a Pt(iv) centre: 100% preference for sp2-sp3over sp3-sp3.
abstract: The oxidative addition of three different organic halides RX to the non-symmetric platinum(ii) mer coordinated dicyclometallated C^N^C complex 1 yielded short-lived six-coordinate platinum(iv) complexes 2(R) (R = Me, allyl, Bn), with the incoming groups trans across the platinum centre. A spontaneous reductive coupling reaction then occurred with, in each case, a completely chemoselective sp2-sp3coupling, and exclusively gave R-3, with the newly introduced R group bonded to the previously cyclometallated aryl ring. Following a recyclometallation reaction, the oxidative addition/reductive elimination cycle was repeated and gave the same selectivity. A one-pot route to doubly alkylating the aryl ring was developed. The observed selectivity might have been predicted on the normal basis of a steric barrier associated with non-flat sp3hybridised groups, but we suggest that it arises from the stereochemistry at the metal, and the orientation of the ligands.
authors.affiliation: Department of Chemistry, Warwick University, Coventry, CV4 7AL, UK. j.rourke@warwick.ac.uk.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Shaw
authors.affiliation: Department of Chemistry, Warwick University, Coventry, CV4 7AL, UK. j.rourke@warwick.ac.uk.
authors.forename: Jonathan P
authors.identifier: http://orcid.org/0000-0002-8961-1021
authors.initials: JP
authors.lastname: Rourke