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Published December 19, 2007 | Supplemental Material
Journal Article Open

Organocatalytic Vinyl and Friedel−Crafts Alkylations with Trifluoroborate Salts


Herein we report the first use of vinyl and heteroaryl trifluoroborate salts as viable substrates for amine-catalyzed conjugate additions. The application of LUMO-lowering iminium catalysis has enabled the highly regio- and enantioselective 1,4-addition of rationally designed trifluoroborate salt nucleophiles to α,β-unsaturated aldehydes. Imidazolidinone 2•HCl was found to catalyze the addition of various BF_3K-derived heteroaryl and vinyl species to a range of enals with excellent levels of enantioselectivity. Importantly, the use of these salts can enable nontraditional regiocontrol as part of a Friedel−Crafts pathway. Boronic acids can also be employed as viable π-nucleophiles for these asymmetric conjugate additions provided that in situ activation to the corresponding boronate species is accomplished. While BF_3K salts are routinely employed in transition metal catalysis, to our knowledge, this is the first use of this activation group for organic catalysis or Friedel−Crafts alkylations.

Additional Information

© 2007 American Chemical Society. Received September 6, 2007. Publication Date (Web): November 22, 2007. Financial support was provided by the NIHGMS (R01 GM078201-01-01) and kind gifts from Merck. S.L. is grateful for a NPSC fellowship with Amgen.

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August 19, 2023
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