Organocatalytic Synthesis of Functionalized Cyclohexanes via Domino Michael/Michael/Cyclization Reaction
碩士 === 國立臺灣師範大學 === 化學系 === 101 === An interesting asymmetric organocatalytic domino reaction by using two components have been developed that gives fully substituted dispirocyclohexanes in one pot. In this study‚ treatment of 2-arylideneindane-1‚3-diones with aldehydes using a catalytic amount of ...
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| Format: | Others |
| Language: | zh-TW |
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2013
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| Online Access: | http://ndltd.ncl.edu.tw/handle/14852639599644927001 |
| Summary: | 碩士 === 國立臺灣師範大學 === 化學系 === 101 === An interesting asymmetric organocatalytic domino reaction by using two components have been developed that gives fully substituted dispirocyclohexanes in one pot. In this study‚ treatment of 2-arylideneindane-1‚3-diones with aldehydes using a catalytic amount of ‚-L-diphenylprolinol silyl ether (5 mol%) and DABCO (20 mol%) in DMF at -20 oC to give fully substituted dispirocyclohexanes via domino Michael/Michael/aldol process with moderate chemical yields and high-to-excellent stereoselectivities (>95:5 dr and up to 99% ee). Besides‚ the absolute stereochemistry is determined by single crystal X-ray analysis of product. On the other hand‚ in another study‚ reaction was carried out under 0 oC by using the (2-(4-nitro-benzylidene)-indan-1‚3-dione) and acrolein as starting materials in DMF in the presense of chiral tertiary amine catalyst (20 mol%) to give pentasubstituted dispirocyclohexanes via cascade Michael/Michael/cyclization process but the chemical yields and enantioselectivity has not been optimized. Successfully synthesis of multisubstituted cyclohexanes and construct two all-carbon quaternary by using two diferrent strategy are more commercial for another synthetic development in the future.
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