132652-68-7Relevant academic research and scientific papers
Asymmetric catalysis with silicon-based cuprates: Enantio- and regioselective allylic substitution of linear precursors
Hensel, Alexander,Oestreich, Martin
, p. 9062 - 9065 (2015)
An enantio- and regioselective allylic silylation of linear allylic phosphates that makes use of catalytically generated cuprate-type silicon nucleophiles is reported. The method relies on soft bis(triorganosilyl) zincs as silicon pronucleophiles that are prepared in situ from the corresponding hard lithium reagents by transmetalation with ZnCl2. With a preformed chiral N-heterocyclic carbene-copper(I) complex as catalyst, exceedingly high enantiomeric excesses are achieved. The new method is superior to existing ones using a silicon-boron reagent as the source of the silicon nucleophile. Zinc about it: Cuprates catalytically generated from bis(triorganosilyl)zinc compounds and a preformed chiral N-heterocyclic carbene-copper(I) complex allow for the highly enantio- and regioselective allylic silylation of various allylic phosphates. The method is broadly applicable with regard to the silicon pronucleophile and the allylic acceptor. It is the first example of asymmetric catalysis with a silicon-based cuprate.
