Organocalcium-mediated nucleophilic alkylation of benzene
作者:Andrew S. S. Wilson、Michael S. Hill、Mary F. Mahon、Chiara Dinoi、Laurent Maron
DOI:10.1126/science.aao5923
日期:2017.12
carbons bound to calcium. Science, this issue p. 1168; see also p. 1132 Alkyl calcium compounds can forge a carbon-carbon bond with benzene by displacing a hydride. The electrophilic aromatic substitution of a C–H bond of benzene is one of the archetypal transformations of organic chemistry. In contrast, the electron-rich π-system of benzene is highly resistant to reactions with electron-rich and negatively
The alkylation reaction is considered to involve the C[bond]Hactivation of cycloalkanes with GaCl(3) at the tertiary center followed by the migration of carbocations and electrophilic aromatic substitution yielding thermodynamically stable products. The stereochemistry of the reaction reveals that GaCl(3) activates the equatorial tertiary C[bond]H rather than the axial tertiary C[bond]H.