A Dual Arylboronic Acid–Aminothiourea Catalytic System for the Asymmetric Intramolecular Hetero-Michael Reaction of α,β-Unsaturated Carboxylic Acids
2014; American Chemical Society; Volume: 16; Issue: 16 Linguagem: Inglês
10.1021/ol501954r
ISSN1523-7060
AutoresTakumi Azuma, Akihiro Murata, Yusuke Kobayashi, Tsubasa Inokuma, Yoshiji Takemoto,
Tópico(s)Asymmetric Hydrogenation and Catalysis
ResumoA bifunctional aminoboronic acid has been used to facilitate for the first time the intramolecular aza- and oxa-Michael reactions of α,β-unsaturated carboxylic acids. The combination of an arylboronic acid with a chiral aminothiourea allowed for these reactions to proceed successfully in an enantioselective manner to afford the desired heterocycles in high yields and ee's (up to 96% ee). The overall utility of this dual catalytic system was demonstrated by a one-pot enantioselective synthesis of (+)-erythrococcamide B, which proceeded via sequential Michael and amidation reactions.
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