Tethered Biginelli condensation of enantioenriched hexahydropyrrolopyrimidines 8 with beta-ketoesters provides efficient asymmetric access to tricyclic guanidines 9 having a syn relationship of the angular C2a and C8a hydrogens. This reaction was employed to realize the first practical enantioselective access to this fragment of batzelladine alkaloids B (2) and E (5). The efficiency of this str...

Modification of a metal surface by a strongly adsorbed chiral organic molecule has proven to be an interesting strategy for heterogeneous chiral catalysis. Platinum chirally modified by cinchona alkaloids, successfully applied for the enantioselective hydrogenation of alpha-ketoesters, is probably the most prominent catalyst based on this concept. Despite considerable research efforts toward un...

Disclosed herein is a stereoselective method for the synthesis of 2,3-furan fused carbocycles bearing adjacent quaternary and tertiary carbon stereocenters. The chemistry is based on an asymmetric addition of b-ketoesters to 2-(1-alkynyl)-2-alkene-1-ones catalysed by natural cinchona alkaloids followed by a silver-catalysed intramolecular cycloisomerisation. By exploiting the distinct catalysis...

A new synthesis of 3H-pyrimidin-4-ones, characterized by four different sets of decorations, is presented. The strategy is based on the synthetic elaboration of readily available α-substituted β-ketoesters that, upon transformation into the corresponding acyl enamines, have been cyclized to give 6H-1,3-oxazin-6-ones. These reactive intermediates have been in turn cleanly converted into highly f...