Synthesis 2012; 44(10): 1542-1550
DOI: 10.1055/s-0031-1290819
special topic
© Georg Thieme Verlag Stuttgart · New York

Copper-Catalyzed Skeletal Rearrangement of O-Propargylic Aryloximes into Four-Membered Cyclic Nitrones – Chirality Transfer and Mechanistic Insight

Itaru Nakamura*
a   Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai 980-8578 Japan, Fax: +81(22)7956602   Email: itaru-n@m.tohoku.ac.jp
b   Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
,
Yu Kudo
b   Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
,
Toshiharu Araki
b   Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
,
Dong Zhang
b   Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
,
Eunsang Kwon
a   Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai 980-8578 Japan, Fax: +81(22)7956602   Email: itaru-n@m.tohoku.ac.jp
,
Masahiro Terada
a   Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai 980-8578 Japan, Fax: +81(22)7956602   Email: itaru-n@m.tohoku.ac.jp
b   Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
› Author Affiliations
Further Information

Publication History

Received: 05 March 2012

Accepted after revision: 09 March 2012

Publication Date:
24 April 2012 (online)


Abstract

Copper-catalyzed skeletal rearrangement of O-propargylic aryloximes (E)-1 were carried out to afford the corresponding four-membered cyclic nitrones 2 in good to excellent yields. The optimal reactions conditions of the highly regioselective reactions involved the use of [CuCl(cod)]2 in acetonitrile at 70 °C. In the case of (Z)-1, however, the reaction proceeded in the absence of the copper catalysts to afford the identical compound 2 in good yields. Furthermore, the reactions were also carried out using chiral substrates (R)-1 in the presence of Cu catalysts to afford (R)-2 with good levels of chirality transfer.

Supporting Information