- Enantioselective Reformatsky Reaction of Ketones Catalyzed by Chiral Indolinylmethanol
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A reliable and practical Reformatsky reaction of ethyl iodide acetate with ketones for the synthesis of chiral β-hydroxyl carbonyl compounds in good yields and excellent enantioselectivities is presented. A readily available dihydroindole derivative was u
- Luo, Renshi,Chen, Miao-Miao,Ouyang, Lu,Chan, Albert S. C.,Lu, Gui
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p. 4805 - 4811
(2020/07/14)
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- Organocatalyzed regioselective and enantioselective synthesis of 1,4- and 1,2-dihydropyridines
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Herein, we introduce one of the first examples of asymmetric organocatalyzed synthesis of 1,2-dihydropyridines, affording enantioselective access to and partially solving regioselectivity challenges in the synthesis of dihydropyridines. We demonstrate that through modification of organocatalysts both 1,2- and 1,4-dihydropyridines (1,2- and 1,4-DHPs) can be obtained with high regioselectivity (ratio of 1,2-DHP/1,4-DHP from 95/5 to 0/100) and enantioselectivity (33% ee for 1,2-DHPs and up to 98% ee for 1,4-DHPs) in good yields (up to 87%).
- Le, Truong-Giang,Pham, Hoai-Thu,Martin, James P.,Chataigner, Isabelle,Renaud, Jean-Luc
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p. 2673 - 2684
(2020/08/07)
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- Asymmetric Deprotonations: Lithiation of N-(tert-Butoxycarbonyl)indoline with sec-Butyllithium/ (-)-Sparteine
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The asymmetric lithiation of N-Boc indoline (1) with s-BuLi/(-)-sparteine and subsequent substitution provides the 2-substituted N-Boc indolines 3 and 5-11 with excellent enantiomeric ratios and in variable yields. The asymmetric lithiation-substitution sequence with N-Boc-7-chloroindoline (12) provides products 13-19 with good enantiomeric ratios. Mechanistic investigation establishes that the enantioselectivities arise from an initial asymmetric deprotonation to provide the enantioenriched and configurationally stable organolithium intermediates (S)-28 and (S)-29, which react stereoselectively with electrophiles.
- Bertini Gross, Kathleen M.,Jun, Young M.,Beak, Peter
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p. 7679 - 7689
(2007/10/03)
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