Oxidative addition of CH2Cl2 to neutral dimeric rhodium diphosphine complexes

Publication date: 15 September 2018Source: Journal of Organometallic Chemistry, Volume 871Author(s): Alberto Mannu, Hans-Joachim Drexler, Richard Thede, Monica Ferro, Wolfgang Baumann, Julia Rüger, Detlef HellerAbstractNeutral dimeric rhodium diphosphine complexes are often employed as catalytic precursors in the presence of the solvent CH2Cl2. The possibility of a collateral reaction between the solvent and the catalytic precursor is never considered as the activation of CH2Cl2 by [Rh2(PP)2 (μ2-Cl)2] complexes is reputed difficult and uncommon. Herein we report the easy formation of three neutral dimeric Rh(III) complexes containing DPPP, DPPB and TangPhos through CH2Cl2 activation as an extension of the few examples reported so far. The system [Rh2 (DPPP)2 (μ2-Cl)2]/CH2Cl2 has been selected for a detailed mechanistic investigation. Kinetic studies based on 31P NMR monitoring combined with metathesis experiments reveal the fundamental role of a 14-electron intermediate [Rh(PP)Cl], which is involved in the CH2Cl2 activation.Graphical abstract

Source: Journal of Organometallic Chemistry - July 22, 2018 Category: Chemistry Source Type: research