We report a highly enantioselective, general catalytic system for the facile synthesis of tertiary stereocenters by protonation adjacent to cyclic ketones. The method relies on catalytic decarboxylative protonation of readily accessible racemic quaternary β-ketoesters. A range of substituted cycloalkanone compounds can be accessed through this process with high levels of enantioselectivity.
[Mohr, Justin T.; Behenna, Douglas C.; Harned, Andrew M.; Stoltz, Brian M. Angewandte Chemie - International Edition, 2005 , vol. 44, # 42 p. 6924 - 6927]