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Asymmetric synthesis of 2,6-substituted dihydropyrone catalyzed by 3-monosubstituted and 3,3′-bisubstituted BINOL titanium complexes
Yu, Hong, Zhang, Ji, Zhao, Yuan-Cong, Wang, Na, Wang, Qin, Yang, Xin-Bin and Yu, Xiao-Qi Asymmetric synthesis of 2,6-substituted dihydropyrone catalyzed by 3-monosubstituted and 3,3′-bisubstituted BINOL titanium complexes Chemical Papers, Vol.62, No. 2, 2008, 187-193
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Document type:
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Článok z časopisu / Journal Article |
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Collection:
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Chemical papers
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| Author(s) |
Yu, Hong
Zhang, Ji
Zhao, Yuan-Cong
Wang, Na
Wang, Qin
Yang, Xin-Bin
Yu, Xiao-Qi
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| Title |
Asymmetric synthesis of 2,6-substituted dihydropyrone catalyzed by 3-monosubstituted and 3,3′-bisubstituted BINOL titanium complexes
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| Journal name |
Chemical Papers
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| Publication date |
2008
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| Year available |
2008
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| Volume number |
62
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| Issue number |
2
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| ISSN |
0366-6352
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| Start page |
187
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| End page |
193
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| Place of publication |
Poland
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| Publisher |
Versita
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| Collection year |
2008
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| Language |
english
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| Subject |
250000 Chemical Sciences
250400 Analytical Chemistry
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| Abstract/Summary |
Asymmetric hetero-Diels-Alder (HDA) reactions of aromatic aldehydes with Danishefsky’s diene derivative were carried out smoothly in the presence of the Ti(IV)-(R)-BINOL (1:1.2) complex to give the corresponding chiral 2,6-disubstituted dihydropyrones under mild conditions. The readily accessible I-Ti(OCH(CH3)2)4 (1.2:1) complex was found to be an effective catalyst for this reaction. Aromatic aldehydes afforded the corresponding products in moderate yields (up to 72 %) with good enantioselectivities (up to 80 % ee). Aromatic aldehydes in presence of the TiCl4-NaOCH3-II (1:4.2:1.2) complex gave the products in higher yields (up to 73 %) with better enantioseletivities (up to 84 % ee).
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