945684-70-8Relevant articles and documents
Asymmetric catalysis with silicon-based cuprates: Enantio- and regioselective allylic substitution of linear precursors
Hensel, Alexander,Oestreich, Martin
supporting information, p. 9062 - 9065 (2015/06/16)
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.
Asymmetric synthesis of tertiary and quaternary allyl- and crotylsilanes via the borylation of lithiated carbamates
Aggarwal, Varinder K.,Binanzer, Michael,De Ceglie, M. Carolina,Gallanti, Maddalena,Glasspoole, Ben W.,Kendrick, Stephanie J. F.,Sonawane, Ravindra P.,Vazquez-Romero, Ana,Webster, Matthew P.
supporting information; experimental part, p. 1490 - 1493 (2011/05/12)
Tertiary allyl- or crotylsilanes have been prepared in high er and dr via the lithiation-borylation reaction of alkyl carbamates with silaboronates. Using a related strategy, quaternary allylsilanes could be accessed in similarly high er.
