Abstract
A series of enantioselective cyclopropanation reactions of substituted alkenes with diazoacetates was investigated in the presence of Cu(OTf)2 with C2-symmetric planar-chiral bridged 2,2′:6′,2″-terpyridines. Planar-chiral terpyridine-copper complexes exhibited moderate diastereomeric excesses with good enantioselectivities of cis-cyclopropane products in catalytic asymmetric cyclopropanation reactions of various styrene derivatives with ethyl diazoacetate. A remote steric effect was found to enhance enantioselectivity for the cyclopropanation induced by a sterically demanding substituent beyond the ansa-bridge of pyridinophane ligands on the other side of the reaction site as a relay of steric influences through flexible cyclophane bridges.
| Original language | English |
|---|---|
| Pages (from-to) | 1898-1903 |
| Number of pages | 6 |
| Journal | Tetrahedron Letters |
| Volume | 56 |
| Issue number | 14 |
| DOIs | |
| Publication status | Published - 2015 Apr 1 |
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Keywords
- Asymmetric cyclopropanation
- Copper carbenoid
- Planar chirality
- Remote steric effect
- Terpyridine
ASJC Scopus subject areas
- Biochemistry
- Organic Chemistry
- Drug Discovery
Cite this
Remote steric effects of C2-symmetric planar-chiral terpyridine ligands on copper-catalyzed asymmetric cyclopropanation reactions. / Mugishima, Nanako; Kanomata, Nobuhiro; Akutsu, Norihiko; Kubota, Hironobu.
In: Tetrahedron Letters, Vol. 56, No. 14, 01.04.2015, p. 1898-1903.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Remote steric effects of C2-symmetric planar-chiral terpyridine ligands on copper-catalyzed asymmetric cyclopropanation reactions
AU - Mugishima, Nanako
AU - Kanomata, Nobuhiro
AU - Akutsu, Norihiko
AU - Kubota, Hironobu
PY - 2015/4/1
Y1 - 2015/4/1
N2 - A series of enantioselective cyclopropanation reactions of substituted alkenes with diazoacetates was investigated in the presence of Cu(OTf)2 with C2-symmetric planar-chiral bridged 2,2′:6′,2″-terpyridines. Planar-chiral terpyridine-copper complexes exhibited moderate diastereomeric excesses with good enantioselectivities of cis-cyclopropane products in catalytic asymmetric cyclopropanation reactions of various styrene derivatives with ethyl diazoacetate. A remote steric effect was found to enhance enantioselectivity for the cyclopropanation induced by a sterically demanding substituent beyond the ansa-bridge of pyridinophane ligands on the other side of the reaction site as a relay of steric influences through flexible cyclophane bridges.
AB - A series of enantioselective cyclopropanation reactions of substituted alkenes with diazoacetates was investigated in the presence of Cu(OTf)2 with C2-symmetric planar-chiral bridged 2,2′:6′,2″-terpyridines. Planar-chiral terpyridine-copper complexes exhibited moderate diastereomeric excesses with good enantioselectivities of cis-cyclopropane products in catalytic asymmetric cyclopropanation reactions of various styrene derivatives with ethyl diazoacetate. A remote steric effect was found to enhance enantioselectivity for the cyclopropanation induced by a sterically demanding substituent beyond the ansa-bridge of pyridinophane ligands on the other side of the reaction site as a relay of steric influences through flexible cyclophane bridges.
KW - Asymmetric cyclopropanation
KW - Copper carbenoid
KW - Planar chirality
KW - Remote steric effect
KW - Terpyridine
UR - http://www.scopus.com/inward/record.url?scp=84925506368&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84925506368&partnerID=8YFLogxK
U2 - 10.1016/j.tetlet.2015.02.103
DO - 10.1016/j.tetlet.2015.02.103
M3 - Article
AN - SCOPUS:84925506368
VL - 56
SP - 1898
EP - 1903
JO - Tetrahedron Letters
JF - Tetrahedron Letters
SN - 0040-4039
IS - 14
ER -