Trimethyl‐ and triethylaluminum undergo enantioselective conjugate addition to 3‐ and 2‐substituted cyclohexenones in the presence of catalytic amounts of a Cu salt and a phosphoramidite ligand L* (see scheme). Thus, chiral quaternary centers can be built with up to 96.6 % ee. Functionalized enones lead to bicyclic structures by a subsequent aldol reaction.

Cyclohexane derivatives Q 0040 Enantioselective Copper-Catalyzed Conjugate Addition to Trisubstituted Cyclohexenones: Construction of Stereogenic Quaternary Centers. -Trialkylaluminum reagents undergo enantioselective addition to substituted cyclohexenones in the presence of copper thiophene carboxylate and biphenol-or binaphthol-based phosphoramidite ligands as catalyst system. -(D'AUGUSTIN, M.; PALAIS, L.; ALEXAKIS*, A.; Angew. Chem., Int. Ed. 44 (2005) 9, 1376-1378; Dep. Chim. Org., Univ. Geneve, CH-1211 Geneve 4, Switz.; Eng.) -S. Adam 26-045