Exo-Selective Intramolecular C-H Alkylation with 1,1-Disubstituted Alkenes by Rare-Earth Catalysts: Construction of Indanes and Tetralins with an All-Carbon Quaternary Center

We report herein the exo-selective, regiospecific annulation of a wide range of functionalized aromatic substrates with 1,1-disubstituted alkenes through C(sp(2))-H and benzylic C(sp(3))-H activation by half-sandwich rare-earth catalysts. This protocol offers a straightforward and atom-efficient route for the synthesis of a family of indane and tetralin derivatives bearing an all-carbon quaternary stereocenter that were difficult to access previously by other catalysts. The reaction mechanism has been elucidated by deuterium-labeling experiments and DFT calculations.

Automated summary

In this study, we report the exo-selective, regiospecific annulation of a wide range of functionalized aromatic substrates with 1,1-disubstituted alkenes through C(sp(2))-H and benzylic C(sp(3))-H activation using half-sandwich rare-earth catalysts. This protocol provides a straightforward and atom-efficient route for synthesizing indane and tetralin derivatives bearing an all-carbon quaternary stereocenter that were previously difficult to access using other catalysts. The reaction mechanism has been elucidated through deuterium-labeling experiments and DFT calculations.