Abstract
Atom-transfer radical cyclization (ATRC) catalyzed by coordinatively unsaturated ruthenium alkoxides 4, [(η5-C5Me 5)Ru(OR)]2, is investigated, and ruthenium methoxide 4a (R=Me) is found to exhibit excellent catalytic activity for the cyclization of N-allyl-α,α-dichloroacetamides at ambient temperature. Addition of some amounts of two-electron donor ligands such as pyridine and triphenylphosphine improves the catalyst efficiency to afford the corresponding γ-lactams in high yields. The high catalytic activity of this catalyst system enables to control the diastereoselectivity of this 5-exo cyclization kinetically. The present 4a/pyridine system is also effective for the 4-exo cyclization of N-vinylacetamides to afford the corresponding β-lactams in quantitative yields. The 4a/pyridine system is also active towards the ATRP of methyl methacrylate (MMA) at room temperature to afford the poly(MMA) with narrow molecular weight distributions (Mw/Mn=1.2) at the initial stage.
| Original language | English |
|---|---|
| Pages (from-to) | 2779-2788 |
| Number of pages | 10 |
| Journal | Tetrahedron |
| Volume | 62 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Mar 20 2006 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Biochemistry
- Drug Discovery
- Organic Chemistry
Cite this
A coordinatively unsaturated ruthenium methoxide as a highly effective catalyst for the halogen atom-transfer radical cyclization of N-allyl dichloroacetamides and related reactions. / Motoyama, Yukihiro; Hanada, Shiori; Shimamoto, Kazuya; Nagashima, Hideo.
In: Tetrahedron, Vol. 62, No. 12, 20.03.2006, p. 2779-2788.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A coordinatively unsaturated ruthenium methoxide as a highly effective catalyst for the halogen atom-transfer radical cyclization of N-allyl dichloroacetamides and related reactions
AU - Motoyama, Yukihiro
AU - Hanada, Shiori
AU - Shimamoto, Kazuya
AU - Nagashima, Hideo
PY - 2006/3/20
Y1 - 2006/3/20
N2 - Atom-transfer radical cyclization (ATRC) catalyzed by coordinatively unsaturated ruthenium alkoxides 4, [(η5-C5Me 5)Ru(OR)]2, is investigated, and ruthenium methoxide 4a (R=Me) is found to exhibit excellent catalytic activity for the cyclization of N-allyl-α,α-dichloroacetamides at ambient temperature. Addition of some amounts of two-electron donor ligands such as pyridine and triphenylphosphine improves the catalyst efficiency to afford the corresponding γ-lactams in high yields. The high catalytic activity of this catalyst system enables to control the diastereoselectivity of this 5-exo cyclization kinetically. The present 4a/pyridine system is also effective for the 4-exo cyclization of N-vinylacetamides to afford the corresponding β-lactams in quantitative yields. The 4a/pyridine system is also active towards the ATRP of methyl methacrylate (MMA) at room temperature to afford the poly(MMA) with narrow molecular weight distributions (Mw/Mn=1.2) at the initial stage.
AB - Atom-transfer radical cyclization (ATRC) catalyzed by coordinatively unsaturated ruthenium alkoxides 4, [(η5-C5Me 5)Ru(OR)]2, is investigated, and ruthenium methoxide 4a (R=Me) is found to exhibit excellent catalytic activity for the cyclization of N-allyl-α,α-dichloroacetamides at ambient temperature. Addition of some amounts of two-electron donor ligands such as pyridine and triphenylphosphine improves the catalyst efficiency to afford the corresponding γ-lactams in high yields. The high catalytic activity of this catalyst system enables to control the diastereoselectivity of this 5-exo cyclization kinetically. The present 4a/pyridine system is also effective for the 4-exo cyclization of N-vinylacetamides to afford the corresponding β-lactams in quantitative yields. The 4a/pyridine system is also active towards the ATRP of methyl methacrylate (MMA) at room temperature to afford the poly(MMA) with narrow molecular weight distributions (Mw/Mn=1.2) at the initial stage.
UR - http://www.scopus.com/inward/record.url?scp=32844474452&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=32844474452&partnerID=8YFLogxK
U2 - 10.1016/j.tet.2006.01.011
DO - 10.1016/j.tet.2006.01.011
M3 - Article
AN - SCOPUS:32844474452
VL - 62
SP - 2779
EP - 2788
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 12
ER -