| (S,E)-5-benzyl-1-((E)-3-(4-cyanophenyl)allylidene)-2,2,3-trimethyl-4-oxoimidazolidin-1-ium | dichloromethane | E Param.: -6.00 |   | Asian J. Org. Chem. 2014, 3, 550-555 10.1002/ajoc.201402009
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| bis(1-methylindol-3-yl)methylium ion |  | E Param.: -5.99 |    | J. Org. Chem. 2015, 80, 8643-8656 10.1021/acs.joc.5b01298
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| 2-phenyl-1,3-dithiolan-2-ylium ion |  | E Param.: -5.91 |    | Acc. Chem. Res. 2003, 36, 66-77 10.1021/ar020094c
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| (S,E)-5-benzyl-2,2,3-trimethyl-1-((E)-3-(4-nitrophenyl)allylidene)-4-oxoimidazolidin-1-ium | dichloromethane | E Param.: -5.90 |   | Asian J. Org. Chem. 2014, 3, 550-555 10.1002/ajoc.201402009
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| (2S,5S)-5-benzyl-3-methyl-4-oxo-1-(3-phenylallylidene)-2-((E)-styryl)imidazolidin-1-ium | dichloromethane | E Param.: -5.90 |   | Asian J. Org. Chem. 2014, 3, 550-555 10.1002/ajoc.201402009
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| (mpa)2CH+ |  | E Param.: -5.89 |      | J. Am. Chem. Soc. 2001, 123, 9500-9512 10.1021/ja010890y
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| 4-aza-6-nitrobenzofuroxan |  | E Param.: -5.86 |    | J. Org. Chem. 2005, 70, 6242-6253 10.1021/jo0505526
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| Vilsmeier ion |  | E Param.: -5.77 |  | Acc. Chem. Res. 2003, 36, 66-77 10.1021/ar020094c
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| (mor)2CH+ |  | E Param.: -5.53 |      | J. Am. Chem. Soc. 2001, 123, 9500-9512 10.1021/ja010890y
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| MacMillan-iminium ion (2nd generation) | MeCN | E Param.: -5.52 |    | Angew. Chem. Int. Ed. 2011, 50, 9953-9956 10.1002/anie.201103683
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| 4,6-dinitrobenzofurazan |  | E Param.: -5.46 |    | J. Org. Chem. 2005, 70, 6242-6253 10.1021/jo0505526
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| methyl(phenyl)methyleneammonium ion |  | E Param.: -5.17 |  | Acc. Chem. Res. 2003, 36, 66-77 10.1021/ar020094c
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| (E)-2-methyl-3-(4-methylbenzylidene)-3H-indol-1-ium ion |  | E Param.: -5.15 |    | J. Org. Chem. 2015, 80, 8643-8656 10.1021/acs.joc.5b01298
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| 4,6-dinitrobenzofuroxan |  | E Param.: -5.06 |    | J. Org. Chem. 2006, 71, 9088-9095 10.1021/jo0614339
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| (E)-2-(tert-butyl)-3-(4-methylbenzylidene)-3H-indol-1-ium | dichloromethane | E Param.: -5.06 |  | Eur. J. Org. Chem. 2016, , 4050-4058 10.1002/ejoc.201600572
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| (E)-1,2-dimethyl-3-(4-methylbenzylidene)-3H-indol-1-ium ion |  | E Param.: -5.05 |    | J. Org. Chem. 2015, 80, 8643-8656 10.1021/acs.joc.5b01298
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| (E)-3-benzylidene-1,2-dimethyl-3H-indol-1-ium ion |  | E Param.: -4.96 |   | J. Org. Chem. 2015, 80, 8643-8656 10.1021/acs.joc.5b01298
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| 2-(4-methoxyphenyl)chromenylium ion |  | E Param.: -4.95 |    | Acc. Chem. Res. 2003, 36, 66-77 10.1021/ar020094c
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| 4-nitro-6-(trifluoromethylsulfonyl)benzofuroxan |  | E Param.: -4.91 |    | J. Org. Chem. 2005, 70, 6242-6253 10.1021/jo0505526
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| (dpa)2CH+ |  | E Param.: -4.72 |      | J. Am. Chem. Soc. 2001, 123, 9500-9512 10.1021/ja010890y
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