Rhodium-catalyzed asymmetric 1,6-addition of aryltitanates to enynones giving axially chiral allenes.
[reaction: see text] The addition of aryltitanate reagents ArTi(OPr-i)4Li to 3-alkynyl-2-en-1-ones in the presence of chlorotrimethylsilane and a rhodium-(R)-segphos as a catalyst proceeded in a 1,6-fashion to give a high yield of axially chiral allenylalkenyl silyl enol ethers with up to 93% ee.
Hayashi
Tamio
T
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan. thayashi@kuchem.kyoto-u.ac.jp
Tokunaga
Norihito
N
Inoue
Kazuya
K