Abstract
This review summarizes our studies of the direct enantioselective alkynylation of α-ketoesters and α-ketiminoesters catalyzed by [bis(oxazoline)phenyl]rhodium(III) ((phebox)Rh(III)) complexes. The reactions provide chiral α-tetrasubstituted propargyl alcohols and propargylamines under proton-transfer conditions in high yield and with high enantioselectivity. The unique nature of (phebox)Rh(III) complexes allows the reactions to occur in the presence of various functional groups, including an electrophilic aldehyde functionality. Mechanistic studies revealed that the generation of (alkynyl)Rh(III) complexes limited the overall reactivity, which led us to use (trimethylsilylethynyl)(phebox)Rh(III) complexes as efficient pre-catalysts. The use of (trimethylsilylethynyl)(phebox)Rh(III) complexes reduced catalyst loading to as low as 0.5 mol%, and expanded the substrate scope to unprecedented α-ketiminophosphonate and cyclic N-sulfonyl α-ketiminoesters.
| Original language | English |
|---|---|
| Pages (from-to) | 637-661 |
| Number of pages | 25 |
| Journal | Heterocycles |
| Volume | 95 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jan 1 2017 |
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All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Pharmacology
- Organic Chemistry
Cite this
Direct enantioselective alkynylation of α-ketoesters and α-ketiminoesters catalyzed by [bis(oxazoline)phenyl]rhodium(III) complexes. / Morisaki, Kazuhiro; Morimoto, Hiroyuki; Mashima, Kazushi; Ohshima, Takashi.
In: Heterocycles, Vol. 95, No. 2, 01.01.2017, p. 637-661.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct enantioselective alkynylation of α-ketoesters and α-ketiminoesters catalyzed by [bis(oxazoline)phenyl]rhodium(III) complexes
AU - Morisaki, Kazuhiro
AU - Morimoto, Hiroyuki
AU - Mashima, Kazushi
AU - Ohshima, Takashi
PY - 2017/1/1
Y1 - 2017/1/1
N2 - This review summarizes our studies of the direct enantioselective alkynylation of α-ketoesters and α-ketiminoesters catalyzed by [bis(oxazoline)phenyl]rhodium(III) ((phebox)Rh(III)) complexes. The reactions provide chiral α-tetrasubstituted propargyl alcohols and propargylamines under proton-transfer conditions in high yield and with high enantioselectivity. The unique nature of (phebox)Rh(III) complexes allows the reactions to occur in the presence of various functional groups, including an electrophilic aldehyde functionality. Mechanistic studies revealed that the generation of (alkynyl)Rh(III) complexes limited the overall reactivity, which led us to use (trimethylsilylethynyl)(phebox)Rh(III) complexes as efficient pre-catalysts. The use of (trimethylsilylethynyl)(phebox)Rh(III) complexes reduced catalyst loading to as low as 0.5 mol%, and expanded the substrate scope to unprecedented α-ketiminophosphonate and cyclic N-sulfonyl α-ketiminoesters.
AB - This review summarizes our studies of the direct enantioselective alkynylation of α-ketoesters and α-ketiminoesters catalyzed by [bis(oxazoline)phenyl]rhodium(III) ((phebox)Rh(III)) complexes. The reactions provide chiral α-tetrasubstituted propargyl alcohols and propargylamines under proton-transfer conditions in high yield and with high enantioselectivity. The unique nature of (phebox)Rh(III) complexes allows the reactions to occur in the presence of various functional groups, including an electrophilic aldehyde functionality. Mechanistic studies revealed that the generation of (alkynyl)Rh(III) complexes limited the overall reactivity, which led us to use (trimethylsilylethynyl)(phebox)Rh(III) complexes as efficient pre-catalysts. The use of (trimethylsilylethynyl)(phebox)Rh(III) complexes reduced catalyst loading to as low as 0.5 mol%, and expanded the substrate scope to unprecedented α-ketiminophosphonate and cyclic N-sulfonyl α-ketiminoesters.
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UR - http://www.scopus.com/inward/citedby.url?scp=85025700767&partnerID=8YFLogxK
U2 - 10.3987/REV-16-SR(S)4
DO - 10.3987/REV-16-SR(S)4
M3 - Article
AN - SCOPUS:85025700767
VL - 95
SP - 637
EP - 661
JO - Heterocycles
JF - Heterocycles
SN - 0385-5414
IS - 2
ER -