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Coupling reactions isocyanate-based

Ricci and co-workers introduced a new class of amino- alcohol- based thiourea derivatives, which were easily accessible in a one-step coupling reaction in nearly quanitative yield from the commercially available chiral amino alcohols and 3,5-bis(trifluoromethyl)phenyl isothiocyanate or isocyanate, respectively (Figure 6.45) [307]. The screening of (thio)urea derivatives 137-140 in the enantioselective Friedel-Crafts reaction of indole with trans-P-nitrostyrene at 20 °C in toluene demonstrated (lR,2S)-cis-l-amino-2-indanol-derived thiourea 139 to be the most active catalyst regarding conversion (95% conv./60h) as well as stereoinduction (35% ee), while the canditates 137, 138, and the urea derivative 140 displayed a lower accelerating effect and poorer asymmetric induction (Figure 6.45). The uncatalyzed reference reaction performed under otherwise identical conditions showed 17% conversion in 65 h reaction time. [Pg.288]

Copper-mediated coupling reactions of / -iodocalixarenes with phthalimide followed by hydrazinolysis should be mentioned as an alternative and independent strategy to obtain p-aminocalixarenes . The carbazole-substituted derivatives 50 (Figure 8) were obtained similarly by Ulhnan coupling . CMPO derivatives (51c), urea compounds (51b), available also via the isocyanates (51a), may be mentioned additionally. Mono- (52) and diimides with acidic functions pointing towards the cavity, and the calix[6]arene-based acetylcholine esterase mimic (53) are more sophisticated examples. [Pg.1406]


See other pages where Coupling reactions isocyanate-based is mentioned: [Pg.210]    [Pg.20]    [Pg.189]    [Pg.595]    [Pg.210]    [Pg.63]    [Pg.320]    [Pg.210]    [Pg.655]    [Pg.150]    [Pg.20]    [Pg.170]    [Pg.185]    [Pg.373]    [Pg.40]    [Pg.467]    [Pg.107]    [Pg.108]    [Pg.108]    [Pg.111]    [Pg.119]    [Pg.115]    [Pg.191]    [Pg.651]    [Pg.115]    [Pg.469]    [Pg.82]    [Pg.96]    [Pg.92]    [Pg.165]    [Pg.225]    [Pg.236]    [Pg.406]    [Pg.387]    [Pg.594]    [Pg.75]    [Pg.327]    [Pg.96]    [Pg.1006]    [Pg.137]    [Pg.138]    [Pg.41]    [Pg.836]    [Pg.40]    [Pg.110]    [Pg.351]   
See also in sourсe #XX -- [ Pg.108 , Pg.109 ]




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Isocyanate-based

Isocyanates reaction

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