A family of rhodium(i) NHC chelates featuring O-containing tethers for catalytic tandem alkene isomerization–hydrosilylation. Issue 3 (25th November 2020)

• Record Type: Journal Article
• Authors: Srivastava, Ravi; Jakoobi, Martin; Thieuleux, Chloé; Quadrelli, Elsje Alessandra; Camp, Clément
• Is Part Of: Dalton transactions. Volume 50:Issue 3(2020)
• Page Start: 869
• Page End: 879
• Publication Date: 2020-11-25
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt03698f
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The catalytic performances in hydrosilylation of alkenes strongly depend on the structure of O-functionalized NHC Rh(i ) complexes. Abstract : The rhodium complex Rh(HL)(COD)Cl, 1, L being a functionalized N-heterocyclic carbene (NHC) ligand with an oxygen-containing pendant arm, has been used as the entry point to synthesize a series of neutral and cationic Rh(i ) O, C chelates. While the Rh–carbene interaction is similar in all these 16-electron complexes, structural analysis reveals that the strength of the Rh–O bond is greatly affected by the nature of the O-donor: R-O − > R-OH > R-OBF3 . These subtle changes in the nature of the O-containing tether are found to be responsible for large differences in the alkene hydrosilylation catalytic activity of these compounds: the stronger the Rh–O interaction, the better the catalytic performances. The most active catalyst, [Rh(L)(COD)], 2, demonstrated good catalytic activity under mild reaction conditions for the hydrosilylation of a range of alkene substrates with the industrially relevant non-activated tertiary silane, 1, 1, 1, 3, 5, 5, 5-heptamethyltrisiloxane (MD H M). Furthermore, this complex is an effective catalyst for the selective remote functionalization of internal olefins at room temperature via tandem alkene isomerization–hydrosilylation.