Enantio- and diastereoselective construction of vicinal quaternary and tertiary carbon centers by catalytic Michael reaction of α-substituted β-keto esters to cyclic enones

Keisuke Majima; Shin Ya Tosaki; Takashi Ohshima; Masakatsu Shibasaki

doi:10.1016/j.tetlet.2005.05.139

Enantio- and diastereoselective construction of vicinal quaternary and tertiary carbon centers by catalytic Michael reaction of α-substituted β-keto esters to cyclic enones

Keisuke Majima, Shin Ya Tosaki, Takashi Ohshima, Masakatsu Shibasaki

Research output: Contribution to journal › Article › peer-review

21 Citations (Scopus)

Abstract

A catalytic enantio- and diastereoselective Michael reaction was achieved to construct vicinal quaternary and tertiary carbon centers in one step. Using 5 mol % of La(O-i-Pr)₃ and 10 mol % of a new N-linked-BINOL type ligand, the reaction of α-substituted β-keto esters to cyclic enones provided the corresponding Michael adducts in up to quantitative yield with a diastereomeric ratio up to 86/14 and enantiomeric excess up to 86% for the major isomer. An alternative catalyst preparation method using La(OTf)₃ instead of La(O-i-Pr)₃ was also examined.

Original language	English
Pages (from-to)	5377-5381
Number of pages	5
Journal	Tetrahedron Letters
Volume	46
Issue number	32
DOIs	https://doi.org/10.1016/j.tetlet.2005.05.139
Publication status	Published - Aug 8 2005
Externally published	Yes

All Science Journal Classification (ASJC) codes

Biochemistry
Drug Discovery
Organic Chemistry

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10.1016/j.tetlet.2005.05.139

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Enantio- and diastereoselective construction of vicinal quaternary and tertiary carbon centers by catalytic Michael reaction of α-substituted β-keto esters to cyclic enones. / Majima, Keisuke; Tosaki, Shin Ya; Ohshima, Takashi et al.
In: Tetrahedron Letters, Vol. 46, No. 32, 08.08.2005, p. 5377-5381.

Research output: Contribution to journal › Article › peer-review

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title = "Enantio- and diastereoselective construction of vicinal quaternary and tertiary carbon centers by catalytic Michael reaction of α-substituted β-keto esters to cyclic enones",

abstract = "A catalytic enantio- and diastereoselective Michael reaction was achieved to construct vicinal quaternary and tertiary carbon centers in one step. Using 5 mol % of La(O-i-Pr)3 and 10 mol % of a new N-linked-BINOL type ligand, the reaction of α-substituted β-keto esters to cyclic enones provided the corresponding Michael adducts in up to quantitative yield with a diastereomeric ratio up to 86/14 and enantiomeric excess up to 86% for the major isomer. An alternative catalyst preparation method using La(OTf)3 instead of La(O-i-Pr)3 was also examined.",

author = "Keisuke Majima and Tosaki, {Shin Ya} and Takashi Ohshima and Masakatsu Shibasaki",

note = "Funding Information: This work was supported by RFTF and a Grant-in-Aid for Encouragements for Young Scientists (A) from the Japan Society for the Promotion of Science (JSPS). We thank Dr. Tsuneaki Yamagata (Osaka University) for X-ray analysis. ",

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AU - Tosaki, Shin Ya

AU - Ohshima, Takashi

AU - Shibasaki, Masakatsu

N1 - Funding Information: This work was supported by RFTF and a Grant-in-Aid for Encouragements for Young Scientists (A) from the Japan Society for the Promotion of Science (JSPS). We thank Dr. Tsuneaki Yamagata (Osaka University) for X-ray analysis.

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AB - A catalytic enantio- and diastereoselective Michael reaction was achieved to construct vicinal quaternary and tertiary carbon centers in one step. Using 5 mol % of La(O-i-Pr)3 and 10 mol % of a new N-linked-BINOL type ligand, the reaction of α-substituted β-keto esters to cyclic enones provided the corresponding Michael adducts in up to quantitative yield with a diastereomeric ratio up to 86/14 and enantiomeric excess up to 86% for the major isomer. An alternative catalyst preparation method using La(OTf)3 instead of La(O-i-Pr)3 was also examined.

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Enantio- and diastereoselective construction of vicinal quaternary and tertiary carbon centers by catalytic Michael reaction of α-substituted β-keto esters to cyclic enones

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