Rearrangement, Gosteli-Claisen

The related Gosteli-Claisen rearrangement of 2-alkoxycarbonyl-substituted propargyl vinyl ethers can also be catalyzed by cationic gold(I) complexes and provides highly substituted furan derivatives. ... 

Representative procedure for the gold-catalyzed Gosteli-Claisen rearrangement/ cycloisomerization of alkoxycarbonyl-substituted propargyl vinyl ethers. Isopropyl 4,5-dimethyl-3-(4-nitrophenyl)juran-2-carboxylat ... 

The feasibility of enantioselective catalysis in on-column reaction chromatography was exemplified by the Gosteli-Claisen rearrangement of allylvinyl ethers (cf. 

Scheme 21.1 Catalytic asymmetric Gosteli-Claisen rearrangement studied by enantioselective on-column reaction GC (ocRGC).

Figure 21.9 Elution profiles between 70 and 120 °C of enantioselective ocRGC of the uncatalyzed Gosteli-Claisen rearrangement of (Z)-1 (last eluted peak) to ( )-2 (first two eluted peaks) in presence of the CSP Chirasil-p-Dex (length 25 m i.d. 250 pm ...

To extend ocRGC to the catalytic asymmetric Gosteli-Claisen rearrangement, the following experimental setup is described. Catalytically active separation columns were used as the micro-capillary reactor and are subsequently coupled with enantioselective separation columns to perform analysis of the reaction products. The inner surface of fused-silica capillaries (i.d. 250 pm) was coated with [Cu (R,R)-Ph-box ](SbFg)2 (R R)-5 dissolved in an inert polysiloxane matrix... 

Figure 21.11 Experimental setup of the stereoselective on-column gas chromatographic experiment (a) to investigate the catalytic asymmetric Gosteli-Claisen rearrangement of (f,Z)- and (Z,f)-3 in presence of the Lewis acid catalyst (ft,ft)-5 dissolved...

The embedded catalyst R,R)-5 provided excellent conversions and enantiomeric ratio values for the catalytic asymmetric Gosteli - Claisen rearrangement of E,Z)-Z to 4a. Notably, the catalyst maintained its activity and selectivity within the investigated temperature range between 65 and 85 °C. 

To obtain the experimental activation parameters and AS of the catalytic asymmetric Gosteli-Claisen rearrangement catalyzed by R,R)-5, the incomplete conversion of (Z, )-3 to 4a and 4b was investigated by temperature-dependent measurements between 65 and 85 °C. Best agreement in the calculation of... 

Johnson, Gosteli, BeUus, and Enzymatic Claisen Rearrangements... 

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