Platinum catalysed hydrosilylation of propargylic alcohols

Abstract

A facile and user-friendly protocol has been developed for the selective synthesis of E-vinyl silanes derived from propargylic alcohols using a PtCl2/XPhos catalyst system. The reaction is generally high yielding and provides a single regioisomer at the β-position with E-alkene geometry. The reaction is extremely tolerant of functionality and has a wide scope of reactivity both in terms of alkynes and silanes used. The catalyst loading has been investigated and it is found that good reactivity is observed at extremely low catalyst loadings. This methodology has also been extended to a one-pot hydrosilylation Denmark-Hiyama coupling.

Platinum Catalysed Hydrostannylation of Terminal Alkynes; Highly Selective Synthesis of Vinyl Stannanes

“…Carbocyclic alcohols 1 b and 1 c proved to be viable substrates, affording the desired stannanes in 82% and 83% yields respectively, with ring size having little effect on reaction yield. Secondary alcohol 1 d also was amenable to the reaction, albeit with a noticeable decrease in isolated yield (55%), which is in keeping with previous reports on platinum catalyzed hydrometallation [25] …”

Porous Organic Polymer as a Heterogeneous Ligand for Highly Regio- and Stereoselective Nickel-Catalyzed Hydrosilylation of Alkyne

“…Next, we turned our attention to exploring various alkynes with PhSiH 3 for hydrosilylation in the presence of a Ni/POL-Xantphos system. With a tendency to undergo multiple couplings to afford multiaddition products, silanes containing multiple hydrides such as PhSiH 3 are usually challenging substrates for selective alkyne hydrosilylation. , Despite previous successful attempts to give ( Z )-β-vinylsilanes with good selectivities, , the highly ( E )-β-selective hydrosilylation of alkynes with PhSiH 3 has rarely been reported . Excitedly, with our Ni/POL-Xantphos catalyst, good yields and selectivities of ( E )-β-vinylsilanes could be obtained, not only for terminal alkynes but also for internal alkynes when using PhSiH 3 as silicon source (Table ).…”

Mild Approach to 2-Acylfurans via Intercepted Meyer–Schuster Rearrangement of 6-Hydroxyhex-2-en-4-ynals

“…The hydroxyl aldehyde 7g was prepared following the general procedure A from bromo aldehyde (352 mg, 1.74 mmol), propargyl alcohol (250 mg, 1.45 mmol), anhydrous THF (13 mL), anhydrous i Pr 2 NH (4 mL), CuI (50 mg, 0.26 mmol), and Pd­(PPh 3 ) 2 Cl 2 (12 mg, 0.0174 mmol), by stirring for 17 h at room temperature. Purification by flash chromatography (4/1 hexane/EtOAc) gave the hydroxy aldehyde 7g (400 mg, 1.36 mmol, 78%) as a pale yellow oil.…”