Aldehydes and ketones form intermediate π complexes with the Gilman reagent, Me2CuLi, at low temperatures in tetrahydrofuran.

@article{Bertz2013AldehydesAK,
  title={Aldehydes and ketones form intermediate π complexes with the Gilman reagent, Me2CuLi, at low temperatures in tetrahydrofuran.},
  author={Steven H. Bertz and Richard A. Hardin and Craig A. Ogle},
  journal={Journal of the American Chemical Society},
  year={2013},
  volume={135 26},
  pages={9656-8}
}
Typical aldehydes and ketones form π complexes with Me2CuLi at low temperatures in tetrahydrofuran. They range in stability from fleeting intermediates at -100 °C to entities that persist up to -20 °C. Three subsequent reaction pathways have been identified.