Copper-catalyzed reaction of alpha-aryldiazoesters with terminal alkynes: a formal [3 + 2] cycloaddition route leading to indene derivatives.
It was discovered that Cu(IPr)Cl-catalyzed reaction of terminal alkynes with alpha-aryldiazoacetates provides indene derivatives, formal [3 + 2] cycloaddition adducts. Excellent regio- and chemoselectivity were observed to afford either 3H- or 1H-indene esters depending on the reaction conditions employed. The reaction is proposed to proceed via tandem processes: alkyne insertion into copper-carbenoid, intramolecular electrophilic attack on the aromatic ring, and then isomerization.
Park
Eun Ju
EJ
Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
Kim
Seok Hwan
SH
Chang
Sukbok
S