Squaramate 5 was prepared from 3,4-diethoxycyclobut-3-ene-1,2-dione (1) and 3,5-bis(trifluoromethyl)aniline (4). Synthesis of the analogous squaramate 3 from 3,4-diethoxycyclobut-3-ene-1,2-dione (1) and 3,5-bis(trifluoromethyl)benzylamine (2) was not successful. Catalytic hydrogenation of alkene 6 gave the amine building block 7. Starting from squaramate 5 and amine building block 8, the desired organocatalyst 3-((3,5-bis(trifluoromethyl)phenyl)amino)-4-(((S)-quinolin-4-yl((1S,2S,4S,5R)-5-vinylquinuclidin-2-yl)methyl)amino)cyclobut-3-ene-1,2-dione (9) was synthesized. All the products were prepared following the literature procedures.
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