Journal of the American Chemical Society, Vol.130, No.2, 398-398, 2008
Enantioselective organo-SOMO catalysis: The alpha-vinylation of aldehydes
The first enantioselective organocatalytce alpha-vinylation of aldehyhed has been accomplished. Selective oxidation of chrial enemies derived from the condensation or aldehydes and a chiral secondary amine catalyst, leads to me production or highly reactive radical cations that exist in an asymmetric environment. These sOMO.activated species undergo direct coupling with readity available potassium organotrifluoroborate salts to yield enantioenriched alpha-vinyl aldehydes. The described reaction procedure achieves carbon-carbon bond formation an efficient manner with consistently nigh levels of enantioinduction and geometrical control for the trans-olefin product. A wide range of both aldehydes end potassium organotrifluroborate salts, including those typically susceptible to oxidative conditions, are accommodated under the reaction conditions. Results herein further demonstrate the capacity of the SOMO catalysis oadomt to achieve asymmetric carbon-carbon bond formations that are difficult to access via traditional methods.