Organocatalyzed Cascade Aza‐Michael/Michael Addition for the Asymmetric Construction of Highly Functionalized Spiropyrazolone Tetrahydroquinolines
Chemistry - An Asian JournalPublished 9 September 2014
Junhua Li, Da‐Ming Du
Citations71
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SJR score0.75
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TL;DR
An organocatalyzed diastereo- and enantioselective cascade aza-Michael/Michael addition of 2-tosylaminoenones to unsaturated pyrazolones has been developed to afford novel chiral spiropyrazolone tetrahydroquinolines containing three contiguous stereocenters.
Abstract
An organocatalyzed diastereo- and enantioselective cascade aza-Michael/Michael addition of 2-tosylaminoenones to unsaturated pyrazolones has been developed to afford novel chiral spiropyrazolone tetrahydroquinolines containing three contiguous stereocenters. This cascade reaction proceeded well with 2 mol% chiral bifunctional tertiary amine squaramide catalyst to give the desired products in excellent yields (up to 99%) with excellent diastereoselectivity (up to >25:1 diastereomeric ratio) and high enantioselectivity (up to 91% enantiomeric excess).
Keywords
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