Complexes of the Gilman Reagent with Double Bonds across the π–σ Continuum
摘要:
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.
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
One-pot synthesis of 2,3-substituted benzo[b]thiophenes via Cu(<scp>i</scp>) catalysed intramolecular cyclisation from dithioesters
作者:Nagarakere. C. Sandhya、Kebbahalli. N. Nandeesh、Kanchugarakoppal. S. Rangappa、Sannaiah. Ananda
DOI:10.1039/c5ra02114f
日期:——
Efficient synthesis of benzo[b]thiophenes from o-halophenyl acetonitrile has been achieved. This novel one-pot procedure involves CuI and pivalic acid catalyzed C–S bond formation using dithioesters followed by a heterocyclization reaction. This efficient protocol has the advantages of one-pot synthesis, short reaction time, good yields (62–78%) and operational simplicity.
已从邻卤代苯基乙腈高效合成苯并[ b ]噻吩。这种新颖的一锅法涉及使用二硫代酯和CuI和新戊酸催化的C–S键形成,然后进行杂环化反应。这种高效的方法具有一锅法合成,反应时间短,产率高(62-78%)和操作简便的优点。
Minimization of Organocuprate Complexity through Self-Organization: Remarkable Orientation Effect in Mixed Cuprate π Complexes
作者:Steven H. Bertz、Richard A. Hardin、Michael D. Murphy、Craig A. Ogle、Joshua D. Richter、Andy A. Thomas
DOI:10.1002/anie.201107060
日期:2012.3.12
where to go: A powerful orientation effect has been observed in complexes of mixedorganocuprates [RTRNTCuLi] and substrates with CC, CN, and CS double bonds (see scheme; Th=thienyl). The preferred geometry of the intermediate complex sets up the facile addition of RT to the double bond, rather than addition of the “dummyligand”, RNT.
他们“知道”去哪里:一个强大的取向效应在混合有机铜[R的复合物中观察到Ť ř NT CuLi]和底物使用C C,C N,和C š双键(参见方案; TH =噻吩基)。中间配合物的优选几何形状建立了将R T容易地添加到双键中,而不是添加了“虚拟配体” R NT。