Direct catalytic asymmetric and -selective vinylogous addition of butenolides to chromones

• Published in: Chemical science (Cambridge) 2020-07, Vol.11 (27), p.717-7176
• Main Authors: Cui, Jin, Kumagai, Naoya, Watanabe, Takumi, Shibasaki, Masakatsu
• Format: Article
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d0sc01914c

An anti -selective catalytic asymmetric Michael-type vinylogous addition of β,γ-butenolides to chromones was developed. The catalyst system developed herein is characterized by tuning of the steric and electronic effects using a proper Biphep-type chiral ligand to invert the diastereoselection, and improvement of the catalyst turnover by a coordinative phenolic additive. The catalytic protocol renders potentially biologically active natural product analogs accessible in good yield with moderate diastereoselectivity and high enantiomeric purity, mostly greater than 99% ee. An anti -selective catalytic asymmetric Michael-type vinylogous addition of β,γ-butenolides to chromones was developed.