The enantioselective palladium-catalyzed allylic alkylation is an established and versatile method today.1) The major drawback of the �Tsuji-Trost reaction� was for a long period its limitation in the type of carbon nucleophiles inasmuch as �soft�, stabilized carbanions have been used almost exclusively.2) The scope of the method can be extended considerably if nonstabilized preformed enolates will function as nucleophiles.3) We report here on the diastereoselective and/or enantioselective allylation of nonstabilized preformed enolates of ketones and lactones as well as doubly deprotonated carboxylic acids.In a representative protocol,5 the lithium enolate of cyclohexanone was submitted to a palladium-catalyzed asymmetric allylic alkylation that occurred in high diastereoselectivity and/or enantioselectivity.The protocol was successfully applied to the lithium enolates of five and six-membered lactones and permitted to obtain enantiomerically pure products with two or three stereogenic centers.Even the dilithium or dimagnesium (Ivanov)-reagents obtained by twofold deprotonation of carboxylic acids (considerd as �hard� nucleophiles) undergo smooth diastereoselective and enantioselective allylic aklylations.1. B. M. Trost, M. L. Crawley, Chem. Rev. 2003, 103, 2921.2. M. Braun, T. Meier, Synlett 2006, 661.3. For a short review, see: M. Braun, T. Meier, Angew. Chem. Int. Ed. 2006, 45, 6952.4. M. Braun, F. Laicher, T. Meier, Angew. Chem. Int. Ed. 2000, 39, 3494; M. Braun, T. Meier, Synlett 2005, 2968; M. Braun, T. Meier, F. Laicher, P. Meletis, M. Fidan, Adv. Synth. Catal.2008, 350, 303.5. M. Braun, P. Meletis, M. Fidan, Org. Synth. 2009, 86, 47.

Asymmetric allylic alkylations with preformed ketone and lactone enolates and doubly deprotonated carboxylic acids

240th National Meeting (2010)

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