Rhodium-catalyzed asymmetric addition of aryl- and alkenylboron
reagents to electron-deficient olefins
T. Hayashi
Department of Chemistry, Graduate School of Science,
Kyoto University, Sakyo, Kyoto 606-8502, Japan
Abstract: Asymmetric 1,4-arylation and -alkenylation was achieved
by use of organoboronic acids or their derivatives in the presence of
a rhodium catalyst coordinated with binap or its related ligands. The
scope of this asymmetric addition is very broad, a,
b-unsaturated ketones, esters, amides, 1-alkenylphosphonates,
and 1-nitroalkenes being efficiently converted into the corresponding
1,4-addition products with over 95% enantioselectivity. The catalytic
cycle in water is proposed to involve three intermediates [aryl-or alkenyl-rhodium
(oxa-p-allyl) rhodium, and hydroxo-rhodium]
by NMR studies on the rhodium intermediates.
*Plenary and invited lectures presented at the 12th
International Symposium on Organometallic Chemistry Directed Towards
Organic Synthesis (OMCOS-12), Toronto, Ontario, Canada, 6-10 July 2003.
Other lectures are published in this issue, pp.
453-695.
Page last modified 20 May 2004.
Copyright © 2004 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web
manager.