118320-27-7Relevant academic research and scientific papers
NMR studies of TMS-halide activated organocopper compounds
Bergdahl, Mikael,Lindstedt, Eva-Lotte,Olsson, Thomas
, p. C11 - C14 (1989)
Conjugate addition to methyl cinnamate in the reactions with methylcopper and lithium dimethylcuprate activated by either trimethylchlorosilane (TMSCl) or trimethyliodosilane (TMSI) has been studied by 1H, 13C, and 29Si NMR spectroscopy.In the presence of TMSI, methylcopper adds to methyl cinnamate.In the reactions with TMSCl, the LiI usually present from the preparation of the methylcopper is necessary for the reaction to take place, and thus the iodine seems to play an important role in the process.The presence of LiI also influences the E/Z selectivity; reactions with MeCu/TMSI, in the absence of LiI give exclusively the Z isomer of the silyl ketene acetal.
ORGANOCOPPER-IODOSILANE COMBINATIONS IN CONJUGATE ADDITIONS
Bergdahl, Mikael,Lindstedt, Eva-Lotte,Nilsson, Martin,Olsson, Thomas
, p. 535 - 544 (2007/10/02)
This paper concerns new possibilities opened by the addition of (mono)organocopper compounds and iodotrimethylsilane (TMSI) to α,β-unsaturated ketones and esters giving the silyl enol ethers and ketene acetals, respectively.We demonstrate the homogeneous addition of methylcopper-tributyl-phosphine-iodotrimethylsilane to methyl cinnamate, the use of organocopper-bromotrimethylsilane combinations, the dominating formation of Z-silyl enol ethers on conjugate addition of methyl- and butylcopper/TMSI to benzalacetone, and the formation of silyl enol ethers in other additions of organocopper compounds and TMSX to conjugated ketones.The Z-selectivity for addition to benzalacetone corresponds to s-cis conformations in ?-complexes between copper(I) chloride and 1-penten-3-one or 3-buten-2-one.The stereoselectivity could support a reaction path via ?-complexes between organocopper-iodotrimethylsilane complexes and s-cis conformers of the substrates.
