Complexes of Gilman Reagents with C−S and C−N Double Bonds: σ or π Bonding?
作者:Steven H. Bertz、Yasamin Moazami、Michael D. Murphy、Craig A. Ogle、Joshua D. Richter、Andy A. Thomas
DOI:10.1021/ja103068h
日期:2010.7.21
degrees C inside the probe of an NMR spectrometer to give high yields of complexes. Typical examples of substrates include carbon disulfide, methyl dithioacetate, methyl dithiobenzoate, thiobenzophenone, ethylene trithiocarbonate, and phenyl isothiocyanate. Evidence suggesting the formal oxidation state of copper in these complexes to be Cu(III) is presented. The last example was particularly interesting
Complexes of the Gilman Reagent with Double Bonds across the π–σ Continuum
作者:Steven H. Bertz、Stephen K. Cope、Richard A. Hardin、Michael D. Murphy、Craig A. Ogle、David T. Smith、Andy A. Thomas、Tara N. Whaley
DOI:10.1021/om300622c
日期:2012.11.26
By using rapid injection NMR at low temperatures, a variety of pi-complexes of lithium dimethylcuprate(I) with C-C, C-N, and C-S double bonds have been prepared and characterized. Complexation is generally accompanied by large upfield changes in chemical shift for the substrate carbon atoms bonded to copper. In the case of alpha,beta-unsaturated carbonyl compounds, the changes for the carbonyl carbons are much smaller in magnitude, which is consistent with the usual eta(2) representation of these structures. It is possible for one ligand to displace another, and in this way an order of stability can be elucidated. Treatment of selected pi-complexes with chlorosilanes or cyanosilanes gives Cu-III intermediates.