Boron trifluoride organocuprate reactions

In the presence of boron trifluoride, organocuprates are added to 1-aza-1,3-butadiene derivatives to give 1,4 addition products in moderate to good yields after reaction with nucleophiles. When the nucleophile is 2-thienyl or 2-furyl, alkylation results in a simple addition on the imine double bond. The intermediate anion is also trapped by an electrophile.229... 

The chiral piperidinones 46 formed by the reaction between Danishefsky s diene and the glycosyl imines are valuable synthons for the synthesis of higher substituted piperidine derivatives. 2,6-Disubstituted piperidinones 49 are obtained by addition of organocuprates complexes with boron trifluoride [53]. The reaction pathway is illustrated in Scheme 30. 

The rate of nucleophilic ring opening of epoxides with unreactive organocuprates has been demonstrated to be vastly enhanced by the addition of boron trifluoride etherate to the reaction mixture. 

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