A heterobimetallic complex featuring a Ti–Co multiple bond and its application to the reductive coupling of ketones to alkenes† †Electronic supplementary information (ESI) available: Experimental procedures, additional spectroscopic data for 1–4, and computational details of 2 and 3. CCDC 1037714–1037716. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc03772c Click here for additional data file. Click here for additional data file.

To explore metal–metal multiple bonds between first row transition metals, Ti/Co complexes supported by two phosphinoamide ligands have been synthesized and characterized. The Ti metalloligand Cl2Ti(XylNP Pr2)2 (1) was treated with CoI2 under reducing conditions, permitting isolation of the Ti/ Co complex [(m-Cl)Ti(XylNPPr2)2CoI]2 (2). One electron reduction of complex 2 affords ClTi(XylNPPr2)2CoPMe3 (3), which features a metal–metal triple bond and an unprecedentedly short Ti–Co distance of 2.0236(9) Å. This complex is shown to promote the McMurry coupling reaction of aryl ketones into alkenes, with concomitant formation of the tetranuclear complex [Ti(m3-O)(NXylP Pr2)2CoI]2 (4). A cooperative mechanism involving bimetallic C]O bond activation and a cobalt carbene intermediate is proposed.