Selective Hydrosilylation of Dienes, Enynes, and Diynes Catalyzed by a Platinum Complex with a Very Bulky NHC Ligand – The Crucial Role of Precise Tuning of the Reaction Conditions

Abstract

Series of various dienes, diynes and enynes were hydrosilylated in the presence of platinum complex [Pt(IPr*OMe)(dvms)] (I) (where IPr*OMe=1,3‐bis{2,6‐bis(diphenylmethyl)‐4‐methoxyphenyl}imidazol‐2‐ylidene, dvtms = divinyltetramethyldisiloxane) to afford selectively the corresponding mono‐ and bissilylated products in high yields. In each case, the process proceeded fully regioselectively according to the anti‐Markovnikov rule. Hydrosilylation of carbon–carbon triple bonds led to exclusive formation of E‐isomers. For the first time, a one‐pot sequential hydrosilylation of a selected 1,3‐enyne and symmetric α,ω‐diene with two different silanes was also achieved. Moreover, the optimized reaction conditions were adopted for successful hydrosilylation of 1,3‐enynes with secondary silanes to yield stereoregular polyenes containing terminal carbon–carbon double bonds.

Latency and Immobilization in Silicone Resin by (NHC)Pt(dvtms) Complexes through a Partially Self-Consuming Ligand

“…19,20,27,28 These complexes have been prepared in a one-pot reaction at room temperature consisting of the imidazolium tetrafluoroborate salt, potassium tert-butoxide, Karstedt's catalyst in xylenes, and toluene for 24 h in the absence of light (Figure 2). 19,20,27,28 The solvent was removed, and the product was redissolved in pentane, filtered through Celite, and isolated in vacuo in good yield. 19,20,27,28 The main challenge encountered while synthesizing the C# ImPt(dvtms) catalysts is that excess Karstedt's catalyst can remain in solution even upon workup.…”

Advances in the Synthesis and Applications of N-Heterocyclic Carbene Metal Complexes with a Focus on the Weak Base Route

“…Platinum mediates the catalytic hydrosilylation of olefins . This metal is widely used in cancer therapy for the treatment of different types of tumors.…”

Influence of Bis‐NHC Ligand on Platinum‐Catalyzed Hydrosilylation of Internal Alkynes

“…Based on our previous research we were aware that the proper design of the NHC ligands in platinum complexes can significantly affect the reaction progress resulting in a great activity and selectivity of the catalyst. [8,15,29,30] We attempted to develop a catalytic system which would increase the efficiency of the platinum-catalyzed hydrosilylation of internal alkynes. The choice of the reactants followed from the fact that, unlike terminal alkynes and alkenes, internal alkynes require quite harsh reaction conditions (high temperature, high catalyst concentration).…”

“…Based on our previous research we were aware that the proper design of the NHC ligands in platinum complexes can significantly affect the reaction progress resulting in a great activity and selectivity of the catalyst [8,15,29,30] . We attempted to develop a catalytic system which would increase the efficiency of the platinum‐catalyzed hydrosilylation of internal alkynes.…”