A general protocol for the synthesis of Pt-NHC (NHC = N-heterocyclic carbene) hydrosilylation catalysts

Abstract

A simple synthetic route, making use of inexpensive and environment-friendly solvent/reagents, is described leading to [Pt(NHC)(L)Cl2] and [Pt(NHC)(dvtms)] (L = DMS, DMSO, Py; dvtms = divynyltetramethylsiloxane) catalysts.

The “weak base route” leading to transition metal–N-heterocyclic carbene complexes

“…As a continuation of the previous work regarding the development of general and robust synthetic methodologies towards transition metal-NHC complexes, Nolan and coworkers performed the first systematic study in the case of platinum. 88 This provided a new method for accessing a variety of well-defined Pt-NHC complexes that are active in the hydrosilylation of alkenes and alkynes, a field in which Pt-NHC complexes hold a prominent position. 89,90 Despite the existence of sporadic reports mentioning the use of a weak base in order to generate Pt-NHC complexes, this proves to be the first general and in-depth investigation (Scheme 19) of such a route in platinum systems.…”

Platinum‐Catalyzed Alkene Hydrosilylation: Solvent‐Free Process Development from Batch to a Membrane‐Integrated Continuous Process

“…More efficient and selective hydrosilylation reactions were obtained using Pt 0 systems based on N ‐heterocyclic carbene (NHC) ligands reported by Markó et al., namely [Pt(NHC)(dvtms)] (dvtms=1,3‐divinyl‐1,1,3,3‐tetramethyldisiloxane), which are highly stable under reaction conditions [20] . Recently, our group has reported the synthesis of Pt 0 as well as Pt II complexes bearing on a number of NHC ligands using a sustainable weak base approach, [21] and as a proof‐of‐concept, one of the new complexes, [Pt(SIPr)(dms)Cl 2 ] [ Pt ‐ I ; SIPr=1,3‐bis(2,6‐diisopropylphenyl)imidazolidine, dms=dimethyl sulfide] was employed as catalyst in a solvent‐free hydrosilylation of 1‐octene ( 1 ) to afford the desired 1,1,1,3,5,5,5‐heptamethyl‐3‐octyltrisiloxane ( 3 ) with an excellent selectivity.…”

A family of rhodium(i) NHC chelates featuring O-containing tethers for catalytic tandem alkene isomerization–hydrosilylation

“…NHC ligands currently play a ubiquitous role in organometallic chemistry, including for the development of novel alkene hydrosilylation catalysts. [18][19][20][21][22][23][24] We recently developed a new functionalized N-heterocyclic carbene (NHC) ligand with an oxygen-containing pendant arm and demonstrated its interest to prepare a range of monometallic and heterobimetallic complexes. [25][26][27][28] Here, we use this ligand platform to generate a family of Rh(I) O,C chelates and explore their catalytic potential in alkene hydrosilylation and in tandem alkene isomerization/hydrosilylation reactions.…”