Highly chemo- and regioselective intermolecular cyclotrimerization of alkynes catalyzed by cationic rhodium(I)/modified BINAP complexes.
[reaction: see text] Cationic rhodium(I)/modified BINAP complexes are effective catalysts for highly regioselective intermolecular cyclotrimerization of terminal alkynes and highly chemo- and regioselective intermolecular cocyclotrimerization of diethyl acetylenedicarboxylate (DEAD) and terminal alkynes. It is a noteworthy example of intermolecular cocyclotrimerization of two different alkynes in terms of catalytic activity, chemo- and regioselectivity, scope of substrates, and ease of operation. The wide applicability of this new cocyclotrimerization procedure is demonstrated in the one-step synthesis of [6]metacyclophane.
Tanaka
Ken
K
Department of Applied Chemistry, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan. tanaka-k@cc.tuat.ac.jp
Shirasaka
Kaori
K