Enantioselective synthesis of axially chiral biaryls through rhodium-catalyzed complete intermolecular cross-cyclotrimerization of internal alkynes.
[reaction: see text] We have developed a cationic rhodium(I)/H8-BINAP complex-catalyzed complete intermolecular cross-cyclotrimerization of internal alkynes with dialkyl acetylenedicarboxylates. This reaction was successfully applied to enantioselective synthesis of axially chiral biaryls utilizing internal alkynes bearing ortho-substituted phenyl and acetoxymethyl in each terminal position. The axial chirality is constructed at the formation of benzene rings with high enantioselectivity (up to 96% ee).
Department of Applied Chemistry, Graduate School of Engineering, and Instrumentation Analysis Center, Tokyo University of Agriculture and Technology, Koganei, Japan. tanaka-k@cc.tuat.ac.jp
Ken
K
Tanaka
Goushi
G
Nishida
Masakazu
M
Ogino
Masao
M
Hirano
Keiichi
K
Noguchi